FMF - Friends of Minerals Forum, discussion and message board

[Bob Harman]

One of my 2 cases at the recent 2018 Cincinnati show. The show theme for minerals was calcite and its many crystal forms.

[Bob Harman]

Two examples of Aragonite sprays on Quartz with some corroding iron oxides (limonite). Both self collected about 10 years ago.

[Bob Harman]

Two more examples of Indiana Millerite from my collection. Both were self-collected about 2007.

[Bob Harman]

One of the so called hallmarks of the rock structure called a quartz geode is that the quartz crystal tips are suppose to point inward toward the center of the cavity. While this is generally true, a very small percentage have other appearances. These are a few; all self collected.

[Bob Harman]

Two unusual examples from my collection.

The first is a 15 cm x 15 cm geode showing a double cavity layer of druzy crystalline quartz tips atop blue-gray microcrystalline quartz (chalcedony).

The second example is an 11 cm x 7 cm oval and bi-septate geode with one cavity showing blue-gray microcrystalline quartz (chalcedony), while the adjacent cavity contains druzy clear quartz crystal tips.

As I understand crystal formation as related to crystal size, the faster the crystal forms, the smaller the crystal might be. So the formation of microcrystalline quartz (chalcedony) implies rapid formation. Interesting how this bi-septate example might have formed. BOB

[Bob Harman]

From Washington County Indiana come the largest geodes, not only in Indiana, but probably in the US Midwest. Also found are many large colorful and very photogenic examples with collectible calcites. I have shown several in previous posts and here are 2 more. BOB

[Bob Harman]

A recent quality find of a Baryte on Quartz

[Bob Harman]

Many geodes that, when opened, happen to break badly, can still be salvaged. Very collectible areas can be culled from the broken examples. These are 2 more such examples. Calcite on Quartz and Calcite on Dolomite.

Rather than being a "geode" the examples now become more traditional "specimens". BOB

[Bob Harman]

Collected about 20 years ago, acquired by me about 10 years ago, with the quarry closing and becoming flooded about 5 years ago, this is now a classic from this now extinct locality.

Examples of this quality, from this locality, are only rarely seen now-a-days. Culled out examples of larger doubly terminated Celestine crystals on Quartz with the limestone matrix are a true rarity.
BOB

[Bob Harman]

A large piece of coarsely grained fossiliferous limestone with a 3 cm Quartz geode of little significance except for the incidental nearby occurrence of a 5 cm vug containing sprays of Aragonite. Self collected about 12 years ago.

[Bob Harman]

More examples of highly collectible Indiana Barites from my collection. All were self collected over the past 15 years.

[Richard Arseneau]

Great finds! I wish I lived in a location where I could collect myself. The closest destination, that is decent, is three hours away and only accessible during low tides. The only stores that sell minerals are in the same location, as is the yearly show I attend lol.

[Bob Harman]

An interesting and unusual small cabinet size addition to any collection, this example from Monroe County Indiana features a "window" into a 5 cm cavity with several very fresh crystals.

[R Saunders]

Pyrite on matrix "dolomite breccia" from Pleasant Ridge, Indiana
Pyrite from. Rensselaer Quarry (Rensselaer Stone Company Quarry; Pleasant Ridge Quarry), Pleasant Ridge, Jasper Co., Indiana, USA.

Well formed, golden colored, crystals many of which are octahedrons with cube modifications on the corners. Also know as, cuboctahedron rough with scaly surfaces, shimmering luster and scaly stepped faces.

122 grams 54 mm Size=small cabinet

[R Saunders]

Quarry flooded. may have tiny Marcasites.