FMF - Friends of Minerals Forum, discussion and message board

[Jordi Fabre]

[xdxucn]

Here's a very cute specimen. The Calcite ball was replaced by SiO2, which has Hedenbergite inclusions (the same as Prase). So, can I call it "Prase pseudomorph after Calcite"?

On the top of the ball, there's a tiny quartz, which adds some visual appeal.

[Tobi]

I love those scepter amethyst crystals from Namibia on https://www.mineral-forum.com/message-board/viewtopic.php?p=40176#40176 - reminds me of my own that i once posted with similar photos:

https://www.mineral-forum.com/message-board/files/amethyst_brandberg2_366.jpg
https://www.mineral-forum.com/message-board/files/amethyst_brandberg3_130.jpg

Please keep posting your collection, it is a pleasure to browse this gallery!

Tobi

[Jordi Fabre]

[xdxucn]

[xdxucn]

"Faden" gypsum

At the Changsha Show this year, I luckily got one piece of phantom gypsum from a local dealer friend.

The gypsum specimen has a habit seen in faden quartz, which is amazing.

[xdxucn]

I think these 2 images show clearly what I mean for "faden gypsum".

[Carles Millan]

[xdxucn]

[Jordi Fabre]

Fixed everything.

Please note that in this section of "Collection photos and Collector's page" we need "IMA names" for each species, so terms like "Selenite" or "Faden" are not welcome in the "Mineral" caption's box. Of course you can use what you want in your descriptive texts (although some FMFers could disagree ;-) ;-)

Also please note that "faden quartz" is a descriptive term for a usually tabular group of quartz crystals with a white thread-like or string-like zone running through the interior. The term "faden" is a German word for "thread".

So, if you want you can use it for a Gypsum but it don't match quite well this species...

[Gerhard Niklasch]

In our original German usage, the qualifier "Faden-xxx" does not automatically imply that xxx="Quartz", although quartz is by far the most common case. (For example, epidote/clinozoisite occasionally provide other examples.) You certainly can't use "Faden" alone in German to refer to such a mineral specimen without appending a species name.

Of course, faden-type growth won't be visible unless the material is clear and transparent and, if colored, sufficiently thin; which limits the candidate species.

Here, based on the pictures, I'm happy with the appearance being described as "faden Gypsum".--

--Nice gallery, and I like the additional points of interest mentioned in the descriptions! Please do keep them coming. :)

Cheers, Gerhard

[xdxucn]

It's so nice that I could get those wrong specimen information corrected, with the help of so many experienced people in this forum. Thank you.

Another thing I'd like to correct is about "quartz10a.jpg": After consulting some more local dealers, and doing some hardness test by myself, I think that piece is "green calcite with quartz on top". Thanks to Jordi.

I'm very glad that people like these photographs. Maybe some people want to know how to get that quality. I use EOS 60D with 100mm macro lens for most mineral photography. I use simple lighting, usually just a desktop lamp, but with a professional studio bulb (5500k temperature which reflect 90% of natural color). I don't have any expensive studio equipment, background, reflection plate, etc. I might shoot mineral photos just on some white or black paper. The most trick part is to remove and replace background digitally, which benefits from my skill and knowledge in computer graphics. I'm considering writing some brief tutorial on how to do this. It might take some time because English is not my native language. When it's finished, I'll put on the forum. :)

Xiao-dong

[Jordi Fabre]

[Don Lum]

[xdxucn]

Glassy clear fluorite cubes with distinctive blue edges and spots on the faces. Some areas are covered with a tan coating of hemimorphite.

Interesting thing is: the blue edge can be seen from certain angle, but becomes invisible from other angles (compare image1 and image2).

[Mike Wood]

Nice little fluorite specimen Xiao-dong! It makes a change for me to see a 'local' specimen on this site - Coldstones Quarry is only 20mins away from me! (I don't collect there as it is a large working [limestone] quarry). Nice example with the strange purple spots/edges.
Mike

[xdxucn]

A thumbnail shows interesting habit of chalcocite: a "nailhead" formed by hexagonal crystals stacking together.

[xdxucn]

Group of stibnite crystals associated with balls of siderite. Displays well from either side.

[xdxucn]

A piece of etched sulfur, looks like canary yellow coral. The specimen exhibits kind of dissolution to an extreme with many 'tunnels' extending deep into the sulfur and with several going all the way through.

[Tobi]

A really weird piece of sulfur ... looks like a bath sponge ;-)