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A general guide for using the Forum with some rules and tips
The information provided within this Forum about localities is only given to allow reference to them. Any visit to any of the localities requires you to obtain full permission and relevant information prior to your visit. FMF is strictly against any illicit activities related to collecting minerals.
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| Search found 240 matches |
| Author | Message |
|---|---|
 Topic: Quartz Twins |
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| Bob Morgan Replies: 6 Views: 2404 |
 Forum: Minerals and Mineralogy Posted: May 08, 2025 17:32 Subject: Re: Quartz Twins |
| I think Pete's suggestion about two parallel crystals is the best explanation. The c-axes would be horizontal in your photo's. There is some indication that their orientation is slightly off with the ... | |
| Topic: Quartz Twins |
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| Bob Morgan Replies: 6 Views: 2404 |
Forum: Minerals and Mineralogy Posted: May 05, 2025 22:27 Subject: Re: Quartz Twins |
| 'Some really nice crystals! - particularly the first from Colorado and the Namibian one. It's nice to see you have an interest in crystal morphologies.
Your crystal with two 'x' faces on the same pr ... |
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| Topic: Star Quartz |
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| Bob Morgan Replies: 3 Views: 5312 |
Forum: Micros & Macros - Images of Minerals Posted: Apr 19, 2025 09:42 Subject: Re: Star Quartz |
| These are so interesting and unique. This is the only instance I know of where quartz takes such development. These appear to be spherules, like that of other minerals. Is there any explanation for h ... | |
| Topic: Wulfenite and Mimetite |
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| Bob Morgan Replies: 17 Views: 191311 |
Forum: Micros & Macros - Images of Minerals Posted: Apr 05, 2025 16:00 Subject: Re: Wulfenite and Mimetite |
| My galena cast after calcite from Bulgaria has some thin flakes of calcite in some areas. Where there is none there are curved striations on the galena surfaces and rounded edges indicating dissolutio ... | |
| Topic: Are there sources for identifying odd shaped crystal habits? |
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| Bob Morgan Replies: 4 Views: 2689 |
Forum: Minerals and Mineralogy Posted: Mar 26, 2025 08:22 Subject: Re: Are there sources for identifying odd shaped crystal habits? |
| For quartz crystal morphology check out Mindat.org. It's in the quartz entry.
When it comes to identifying quartz faces, a face shape is determined by the faces adjoining it. I find it most helpful t ... |
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| Topic: Are there sources for identifying odd shaped crystal habits? |
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| Bob Morgan Replies: 4 Views: 2689 |
Forum: Minerals and Mineralogy Posted: Mar 25, 2025 11:27 Subject: Re: Are there sources for identifying odd shaped crystal habits? |
| The octahedral face in your first photo is a prism face with three rhombohedral or termination face edges toward one end and three toward the other. The other two edges are of two adjoining prism face ... | |
| Topic: Libyan Desert Glass Structure |
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| Bob Morgan Replies: 60 Views: 91049 |
Forum: Minerals and Mineralogy Posted: Mar 17, 2025 16:50 Subject: Re: Libyan Desert Glass Structure |
| This discussion is far beyond my pay grade but thanks to you all understandable.
Perhaps you might be interested in the latest issue of Elements magazine. It is oriented around the role of water in v ... |
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| Topic: Port Mulgrage field trip for Pyrite specimens |
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| Bob Morgan Replies: 2 Views: 2224 |
Forum: Mines and Mineral Localities Posted: Mar 11, 2025 08:11 Subject: Re: Port Mulgrage field trip for pyrite specimens |
| Similar pyritized fossils are found at Alden, New York and most have the same problem. Some are actually stable. They are rare and highly prized.
My friend keeps his on his toaster oven in the kitche ... |
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| Topic: A true morphological twin of quartz according to the Dauphiné law. |
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| Bob Morgan Replies: 5 Views: 3281 |
Forum: What is it? - Where is it from? Posted: Mar 04, 2025 21:01 Subject: Re: A true morphological twin of quartz according to the Dauphiné law. |
| Amir Akhavan wrote a well-illustrated article that reveals how to identify r from z faces using the features on rhombohedral faces as well as how to distinguish right-handed from left-handed. It's in ... | |
| Topic: It's Tucson Time Again - 2025 |
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| Bob Morgan Replies: 110 Views: 49479 |
Forum: News about Shows Posted: Feb 24, 2025 10:58 Subject: Re: It's Tucson Time Again - 2025 |
| Thanks for your reports on what is wonderfully spectacular and stunningly beautiful. It's a real public service.
I go to Tucson for things that don't make these reports. This year I ran across two ne ... |
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| Topic: Calcite crystal habit |
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| Bob Morgan Replies: 3 Views: 2182 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 24, 2025 09:47 Subject: Re: Calcite crystal habit |
| They are the unit or cleave rhomb with Miller Index of [10-1,1}. | |
| Topic: Need assistance to distinguish the type of this gemstone |
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| Bob Morgan Replies: 2 Views: 2939 |
Forum: Minerals and Mineralogy Posted: Jan 30, 2025 22:01 Subject: Re: Need assistance to distinguish the type of this gemstone |
| It's a garnet. | |
| Topic: It's Tucson Time Again - 2025 |
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| Bob Morgan Replies: 110 Views: 49479 |
Forum: News about Shows Posted: Jan 24, 2025 19:34 Subject: Re: It's Tucson Time Again |
| I purchased something years ago like your malachite that was from Zaire - no other locality info - that was called a pseudomorph after barite. It is more like your third specimen - platy and less pris ... | |
| Topic: Limonitized garnet? |
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| Bob Morgan Replies: 36 Views: 13091 |
Forum: What is it? - Where is it from? Posted: Jan 24, 2025 07:32 Subject: Re: Limonitized garnet? |
| The square outline with 90 degree angles is made by 4 dodecahedral faces around the middle of the crystal as you look down on it from the top. In the first photo there are still 4 faces forming a pyra ... | |
| Topic: Limonitized garnet? |
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| Bob Morgan Replies: 36 Views: 13091 |
Forum: What is it? - Where is it from? Posted: Jan 23, 2025 22:31 Subject: Re: Limonitized garnet? |
| It appears to me that there is a 4 sided pyramid at the top and another at the bottom and 4 faces around the middle to be a rhombic dodecahedron. I can't be sure from the photos, after all, it's a rou ... | |
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