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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 07, 2016 09:29 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Monroe Reservoir, more commonly known as Lake Monroe or Monroe Lake, is a reservoir built by the U.S. Army Corps of Engineers in 1964. It is the water supply for Bloomington Indiana and several nearby smaller communities. It dams up Salt Creek and is used for flood control in southern Indiana. Its normal level (pool level) is 538 feet (above sea level) and the spillway, used as a parking lot and recreational entry to the lake is 552 feet. Two times since 1964 has the spillway been overrun by high water.
The spillway was cut out of a limestone ridge that runs along a portion of the Lake's South shore. The spillway cut is about 75 feet high on both sides and about the width of a U.S. football field. Local collectors can, with some effort, get to several levels hi up on the spillway rock walls to hunt geodes and fossils. These are 5 pix of 3 examples.
These geodes commonly have thin transparent and lustrous pale yellow terminated Baryte along with peculiar frosty calcites. Dolomite and other minerals are very rare. Since the geodes are removed from surrounding limestone which has only recently become exposed, they are usually quite fresh and bright.
Mineral: | Barite and Calcite on Quartz and with Dolomite |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | geode cavity is 15 x 13 cm largest calcite is about 5 cm and the barites are about 2.5 cm |
Description: |
Baryte and calcite on quartz with very minor dolomite
Monroe Reservoir spillway, southern Monroe County, Indiana , USA |
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28591 Time(s) |
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Mineral: | Calcite and Barite on Quartz |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | calcites up to 3.0 cm, barite up to 2.5 cm |
Description: |
Note the frosty appearance of the calcites |
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28571 Time(s) |
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Mineral: | Calcite and Barite on Quartz |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | calcites up to 3.0 cm, barite up to 2.5 cm |
Description: |
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28544 Time(s) |
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Mineral: | Calcite and Barite on Quartz |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | calcites up to 4.0 cm barite up to 2.5 cm |
Description: |
note the frosty appearance of the calcites |
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28559 Time(s) |
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Mineral: | Calcite and Barite on Quartz |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | calcites up to 4.0 cm, barite up to 2.5 cm |
Description: |
note the frosty appearance of the calcites |
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28603 Time(s) |
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GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
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Posted: Jun 07, 2016 15:21 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Very nice Bob!
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 11, 2016 18:43 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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In 2013, while field collecting at the Indiana rte 56 road cuts in Washington County, a fellow pulled off the road near my collecting. When this happens, I get a little anxious as to what the stranger's motives might be. This fellow though, was a friendly local who was interested in what I was doing and proceeded to tell me that he lived nearby with considerable surrounding land. He had a stream in a ravine and had seen geodes in it and said, if I wanted, I could explore the area. In general going onto private property is no so easy here in the U.S. Midwest, but I thanked him.
The next time I was down there, I made it a point to seek out his ravine with not much real hope as these situations rarely lead to anything substantial. The site was a steep heavily wooded rocky ravine with a sharp bend and a shallow stream coursing thru the ravine. The rocky walls of the ravine actually hosted a few large and very large promising geodes so I became rather enthused. The whole site is not very big and over these past 2 years I have found about a dozen very collectible and hi end examples. These 2 pictured are probably the 2 best examples. The very large example has been shown to several dealers at the larger shows and they suggest culling out the area with the calcites to make a specimen rather than a geode, but so far, I have resisted.
Mineral: | calcite on quartz |
Locality: | Washington County, Indiana, USA | |
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Dimensions: | Geode cavity is greater than 30 cm, Calcite area is about 20 cm |
Description: |
Rocky wooded ravine on private land Washington County, Indiana U.S.A.
Collected 2014 |
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28564 Time(s) |
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Mineral: | Calcite on Quartz |
Locality: | Washington County, Indiana, USA | |
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Dimensions: | the geode is about 24 cm and the calcites are up to 2.5 cm |
Description: |
Rocky wooded ravine on private land Washington County , Indiana U.S.A.
Collected 2015 . This picture was taken as part of my recent display case at the 2016 Cincinnati Ohio mineral show |
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28425 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 12, 2016 09:28 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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An extremely unusual occurrence is this hyalite opal on the crystal tips of otherwise rather ordinary quartz. Of my 2 examples, this is the better one. I have never seen any others.
Defined as a colorless rather amorphous glass like silica or quartz with about 3% - 5% water, this form of quartz may be widely found, but apparently not, as far as I know, in Indiana geodes.
Mineral: | Opal (variety hyalite) on quartz |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | geode is 11 cm, the opal area is 2 cm |
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28403 Time(s) |
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Mineral: | Opal (variety hyalite) on quartz |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | opal area is 2 cm |
Description: |
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28354 Time(s) |
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Mineral: | Opal (variety hyalite) on quartz |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | opal area is 2 cm |
Description: |
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28368 Time(s) |
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Jamison Brizendine
Joined: 27 Feb 2014
Posts: 128
Location: Northeast Ohio
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Posted: Jun 13, 2016 08:14 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Bob, does the hyalite fluoresce like the Mexican and African hyalite?
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 14, 2016 15:50 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Perhaps I should have started my postings with examples of simple quartz geodes, after all they are the basis of all the others with the secondary minerals upon the quartz. Ordinary quartz geodes are found by the millions in south central Indiana. Novices and casual collectors most commonly collect rather ordinary examples with little collector appeal or value to the more experienced collectors. Like with all field collected mineral specimens, it takes a bit of searching and luck to find truly top quality or unusual examples.
These 3 large examples, all from locations in Monroe County Indiana, represent higher quality and more unusual finds. They appear much better in person with more 3 dimensionality and more contrasting areas than pictures can show.
I will be posting more hi quality and unusual examples of quartz only geodes in the coming weeks and months.
Mineral: | Quartz |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | geode cavity is 13 cm |
Description: |
quartz geode A large superior example with large round clean cavity, thin rind, no iron staining and one generation of quartz. |
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28249 Time(s) |
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Mineral: | Quartz on Quartz (variety chalcedony) |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | geode cavity is about 10 cm with a thick rind |
Description: |
crystalline quartz on blue chalcedony (microcrystalline quartz) at least 3 generations of quartz. Crystalline quartz topped by blue chalcedony and then covered by crystalline quartz. Perfectly fresh with no iron staining or degeneration and corrosion. |
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28228 Time(s) |
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Mineral: | Quartz |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | geode is about 18 cm with a very thick rind |
Description: |
quartz and microcrystalline quartz at least 4 generations of crystalline and microcrystalline quartz with the cavity lined by smoky quartz. This example weighs nearly 18 lbs. |
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28232 Time(s) |
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Mineral: | Quartz |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | geode is 18 cm, cavity is about 9 cm in greatest dimension |
Description: |
quartz and microcrystalline quartz smoky quartz lines the cavity |
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28236 Time(s) |
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Matt_Zukowski
Site Admin
Joined: 10 Apr 2009
Posts: 707
Location: Alaska
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Posted: Jun 14, 2016 16:48 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Do you do anything special when you break open and then trim these geodes? How do you get them looking so good?
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 14, 2016 17:05 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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HI MATT, Thanks for looking! So while I am now slowing down, when I was actively field collecting, I had to open many many examples to find the few that look like this.
Those that are still in surrounding matrix usually are fresh and don't need much except mechanical trimming with a splitter. Those examples like the just posted 3 quartz geodes, also did not need anything done except to open them as they were found whole and unbroken. If they had been iron stained or otherwise dingy, they would have only made our garden or been wholesaled. I do have lots of nice examples (huge big collection to the dismay of my wife, but no one else!) I only display and photo the very best of my examples that usually did not need much cleaning or prep attention. CHEERS.....BOB
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GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
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Posted: Jun 14, 2016 18:15 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Bob Harman wrote: | Perhaps I should have started my postings with examples of simple quartz geodes, after all they are the basis of all the others with the secondary minerals upon the quartz. Ordinary quartz geodes are found by the millions in south central Indiana. Novices and casual collectors most commonly collect rather ordinary examples with little collector appeal or value to the more experienced collectors. Like with all field collected mineral specimens, it takes a bit of searching and luck to find truly top quality or unusual examples.
These 3 large examples, all from locations in Monroe County Indiana, represent higher quality and more unusual finds. They appear much better in person with more 3 dimensionality and more contrasting areas than pictures can show.
I will be posting more hi quality and unusual examples of quartz only geodes in the coming weeks and months. |
Bob, Really enjoying your posts! Bob
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 17, 2016 12:27 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Of course this forum is primarily about minerals, but here is something a little different.
In Indiana where geodes might be found there are localities primarily in Monroe and Washington Counties that have mineral replaced fossils. Often, the original invertebrate fossil is easily recognized and now completely replaced by silica. Quartz replaced fossils; silicified or geodized fossils as they are called. As my pictures show, they can be hollow, with crystals in the cavity, or solid. These invertebrates are Mid-Mississippian age or about 425 million years old. They are quite common if you know where to look and are sought after by both fossil and Midwest mineral collectors.
This is distinct from minerals associated with fossils like the calcites in clams from Florida or the vivianite associated with Bolivian fossils, these examples represent complete mineral replacement of the fossil. They are similar to pyritized fossils.
Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | about 6 cm greatest dimension |
Description: |
quartz replacing a fossil brachiopod this example is hollow with smoky quartz crystals on chalcedony |
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28057 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | about 6 cm maximum dimension |
Description: |
quartz replacing a brachiopod fossil smoky quartz crystals on chalcedony |
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28037 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | about 4 cm to 6 cm |
Description: |
silicified fossils (geodized fossils) various examples from southern Monroe county. Many have remaining bits of the shell easily noted, but all are now geodes or silicified fossils. |
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28154 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | 5 cm |
Description: |
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27984 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | 5.5 cm |
Description: |
silicified fossil brachiopod bits of the remaining shell are easily noted. |
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27997 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | these range from 2.5 cm to about 6 cm |
Description: |
silicified fossil gastropods (snails) |
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27992 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | about 5.0 cm and 6.5 cm |
Description: |
silicified fossil gastropods (snails) 2 distinctly different species |
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28028 Time(s) |
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Mineral: | Quartz replacing fossil |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | from 3 cm to about 7 cm |
Description: |
silicified fossils (geodized fossils) silicified cephalopods, a crinoid head and crinoid stems and horn coral; all are now geodes. As they have not been opened, one can only speculate whether they are solid or hollow. |
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27995 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 18, 2016 13:48 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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About 1963, when most quarries were open to weekend collecting, fluorite was discovered in the May Quarry (Fort Wayne Sand and Gravel Quarry) near the city of Fort Wayne in Allen County Indiana. Within weeks, the quarry was overrun by collectors and shortly thereafter most unauthorized collecting was stopped. Now only clubs, with management permission, gain occasional access to the quarry.
This example has several crystals in a small vug. The largest crystal measures about 4.5cm x 3.0cm x 3.0cm. Those collectors familiar with these examples can tell them from many similar Ohio quarry crystals. Over the years I have been shown a couple of examples with accompanying white bladed celestine claiming to be from Fort Wayne. Not true as no celestine has ever reliably been reported from this quarry. All fluorite with celestine comes from NW Ohio quarries.
The last time I collected in this quarry was with a 2008 club field trip. No one found much of anything. Then upon driving back to the quarry office to check out, we passed Volkswagen size boulders lining the gravel road to the office. They had been there for years. Checking them out, one had voids filled with similar cubes of fluorite crystals. We had a front end loader help break up the boulder and we went home with several nice specimens.
Mineral: | fluorite |
Locality: | May Stone and Sand Quarry (Hoosier Sand and Gravel Quarry), Fort Wayne, Allen County, Indiana, USA | |
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Dimensions: | largest fluorite is 4.5 cm x 3.0 cm |
Description: |
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27829 Time(s) |
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Mineral: | fluorite |
Locality: | May Stone and Sand Quarry (Hoosier Sand and Gravel Quarry), Fort Wayne, Allen County, Indiana, USA | |
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Dimensions: | largest fluorite is 4.5 cm x 3.0 cm |
Description: |
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27842 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 21, 2016 17:47 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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In Indiana quartz can do strange and interesting things, much like pictures of quartz from many worldwide locations. These 2 examples, from the Harrodsburg road cuts in southern Monroe County show interesting crystal patterns.
Mineral: | Quartz (variety milky quartz) on Calcite |
Locality: | State Route 37 road cuts, Harrodsburg, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | the specimen max dimension is 12 cm the calcite is 5 cm |
Description: |
groups of small milky quartz crystals sprinkled over the calcite. Minor dolomite in the background |
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27700 Time(s) |
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Mineral: | Quartz with Calcite and Dolomite |
Locality: | State Route 37 road cuts, Harrodsburg, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | the quartz "stalactite" is 2.6 cm |
Description: |
Quartz with a calcite and dolomite in the background A 7 cm geode with an interesting 2.6 cm "stalactitic" grouping of small quartz crystals |
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27702 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jun 29, 2016 12:05 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Over the years one of the steadiest and most prolific of high quality calcite producers has been the Berry Materials Quarry in North Vernon Indiana. Several pictures of North Vernon calcites have already been pictured on the site before this one.
Mineral: | Calcite |
Locality: | Berry Materials Corp. Quarry, North Vernon, Jennings County, Indiana, USA | |
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Dimensions: | the calcite is 7 cm max dimension |
Description: |
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27519 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jul 02, 2016 07:58 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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A very large (21 cm) and heavy Harrodsburg road cut geode collected about 11 years ago. This example is interesting in that it has a large isolated 8 cm rhombohedral calcite and a nearby isolated single 4.7 cm Baryte crystal. The translucent/transparent Baryte crystal is color zoned with micro marcasite inclusions. The area of interest in this example was suggested for culling out from the rest of the geode, but, too date, has been kept intact.
Mineral: | Barite and Calcite on Quartz |
Locality: | State Route 37 road cuts, Harrodsburg, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | geode is 21 cm calcite is 8 cm barite is 4.7 cm |
Description: |
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27418 Time(s) |
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Mineral: | Barite and Calcite on Quartz |
Locality: | Harrodsburg area, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | calcite is 8 cm barite is 4.7 cm |
Description: |
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27391 Time(s) |
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Mineral: | Barite on Quartz |
Locality: | Harrodsburg area, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | barite is 4.7 cm |
Description: |
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27422 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jul 07, 2016 09:39 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Casual and weekend geode collectors in Indiana and other geode locations throughout the Midwest most commonly find "field and stream" geodes. This is the name given to those geodes that long ago have weathered out from the limestone matrix and are now found loose in the stream beds and plowed farm fields. The vast majority of these are weather worn, dingy, with corroded and degenerating secondary minerals in the cavity. Only an infrequent example is fresh inside. Experienced collectors shy away from these examples, but you commonly see them offered for sale at roadside stands and Midwest regional rock shows.
Locality: | Washington County, Indiana, USA | |
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Description: |
_Rural Washington County A roadside stand selling field and stream geodes in rural Washington County |
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27220 Time(s) |
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Description: |
-Field and stream geodes for sale at a recent Bloomington rock show |
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27191 Time(s) |
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Description: |
_Field and stream geodes for sale at a recent Bloomington rock show |
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27247 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jul 14, 2016 08:02 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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Two geodes from the Monroe Reservoir spillway locality. The cm ruler is for scale showing that these examples can be quite small or quite large and heavy.
The larger example shows bright multicolored dolomites (pearly pink at 6 o'clock, orange yellow at the 5 and 7-8 o'clock positions and additional scattered bright brick red groupings elsewhere) along with a couple of terminated calcites and small intergrown Barytes, all on quartz.
Mineral: | Dolomite, Calcite, Barite on Quartz |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | see ruler for scale; the larger example is 23 cm with a 13 cm cavity |
Description: |
multicolored dolomite, calcite, and minor Baryte all on quartz |
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27098 Time(s) |
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Mineral: | Dolomite, Calcite, Barite on Quartz |
Locality: | Monroe Reservoir spillway, Monroe County, Indiana, USA | |
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Dimensions: | geode cavity is 13 cm |
Description: |
multicolored dolomites, calcite and minor Baryte on quartz the calcites are about 5.5 - 6.0 cm in max dimension |
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27104 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jul 17, 2016 08:03 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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This 13cm - 14cm geode with a 10cm cavity is superficially similar to the previous example, but there are several important differences. The calcites in the previous example were of rhombohedral crystal type while this example has intergrown scalenohedral crystals, several of which are nicely terminated. Also these crystals have many visible marcasite inclusions while the previous example had calcites free of inclusions. Finally, there is no visible Baryte in the current example.
Mineral: | Calcite with Marcasite inclusions on Dolomite and Quartz |
Locality: | State Route 37 road cuts, Harrodsburg, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | geode is about 14 cm, cavity is about 10 cm, largest calcite is about 4.5 cm |
Description: |
intergrown calcites with marcasite inclusions and multicolored dolomite on quartz |
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27040 Time(s) |
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Mineral: | Calcite with Marcasite inclusions on Dolomite and Quartz |
Locality: | State Route 37 road cuts, Harrodsburg, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | geode is about 14 cm, cavity is about 10 cm, largest calcite is about 4.5 cm |
Description: |
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27001 Time(s) |
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Mineral: | Calcite with Marcasite inclusions on Dolomite and Quartz |
Locality: | State Route 37 road cuts, Harrodsburg, Clear Creek Township, Monroe County, Indiana, USA | |
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Dimensions: | geode is about 14 cm, cavity is about 10 cm, largest calcite is about 4.5 cm |
Description: |
as above; largest calcite is about 4.5 cm |
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27005 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jul 24, 2016 08:47 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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While several secondary minerals are very common in quartz geodes, there are a number of rarely found secondary minerals. One of these is fluorite. Few examples exist and these seem to only be found in Harrison County examples as I have never heard of or seen a reliable example from any other Indiana county.
Mineral: | Fluorite on Quartz |
Locality: | Corydon Stone Co. Quarry, Corydon, Harrison County, Indiana, USA | |
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Dimensions: | geode is 2.5 cm fluorite is 0.4 cm |
Description: |
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26779 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jul 25, 2016 12:35 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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I have exhibited at the Cincinnati Ohio show for about the last 8 years or so. For those who have attended this show, it is one of the larger US Midwest regional shows with many hi quality displays. Some years I have one case, some years 2 cases. One of my favorite topics has been the large and colorful calcite on dolomite geodes of Washington County. These have always been well received and, for persistent collectors, the roadcut has been a steady producer of display quality examples. These pix are of my 2011 case and the second of my 2 cases for newer finds at the 2015 Cincinnati show.
Mineral: | Calcite on Dolomite. Sphalerite and Barite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | Variously sized geodes |
Description: |
my 2011 case. Calcites on dolomite; also a sphalerite and Baryte example By far the most common combination are the calcite on dolomite geodes, but nice quartz and dolomite geodes along with sphalerite crystals can also be found. Geodes with Baryte crystals are rare at this locality. |
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26653 Time(s) |
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Mineral: | Calcite on Dolomite. Sphalerite and Barite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | variously sized geodes |
Description: |
my 2011 case. Calcites on dolomite also a sphalerite and Baryte geode |
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26647 Time(s) |
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Mineral: | Calcite on Dolomite. Sphalerite and Barite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | variously sized geodes |
Description: |
my 2011 case. Calcite on dolomite also a sphalerite and Baryte containing geode |
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26670 Time(s) |
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Mineral: | Calcite on dolomite. Sphalerite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | variously sized geodes |
Description: |
my 2015 case of new finds. Calcite on dolomite, also sphalerite |
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26792 Time(s) |
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Mineral: | Calcite on dolomite. Sphalerite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | variously sized geodes |
Description: |
calcite on dolomite, also sphalerite |
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26657 Time(s) |
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Mineral: | Calcite on dolomite. Sphalerite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | variously sized geodes |
Description: |
calcite on dolomite, also sphalerite |
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26651 Time(s) |
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Mineral: | Sphalerite in Dolomite |
Locality: | State Route 56 road cut, Canton, Washington County, Indiana, USA | |
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Dimensions: | both geodes are about 5 cm; the sphalerite are about 3.5 cm |
Description: |
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26630 Time(s) |
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Aug 04, 2016 08:33 Post subject: Re: A mineralogical trip through the states of USA - Indiana |
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In previous posts I have shown varieties of quartz in Indiana geodes. While common quartz crystal tips and microcrystalline quartz as the variety chalcedony are extremely common in geodes, finding an Indiana double cavity geode with a dividing septum with crystalline quartz in one cavity and microcrystalline quartz (chalcedony) in the other cavity seems exceptionally uncommon. One can only imagine under what formation conditions these 2 cavities with their respective crystals came to be.
Mineral: | Quartz and Quartz (variety chalcedony) |
Locality: | Monroe County, Indiana, USA | |
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Dimensions: | geode is 13 cm x 6 cm. Each cavity is about 6 cm max dimension |
Description: |
quartz and microcrystalline quartz (chalcedony)
the geode shows typical scattered rusty iron oxide staining and the lower cavity shows typical bluish-gray chalcedony |
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Viewed: |
26472 Time(s) |
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