FMF - Friends of Minerals Forum, discussion and message board

[Conor Quinlan]

Hello Everyone,

Recently I acquired a superb natural blue topaz w/ albite var cleavelandite which was added to my showcase collection & which I also shared on FMF 05/07; please click the link below to view the post page & the full images of the specimen:
https://www.mineral-forum.com/message-board/viewtopic.php?p=71728#71728

I have been combing the specimen w/ a 10x loupe & discovered at least 3 distinct tiny unknown minerals ranging b/t (0.2 - 1.0 mm) in size & all w/ very different crystalline structures! The blue topaz crystals contain inclusions of all 3 unknown minerals & there is at least 1 exhibited on the matrix!

1. The more common unknown mineral with several individuals has a dark green color & plate like, hexagonal crystals. Found on the matrix & inside the smaller topaz crystals
2. At least a few individual crystalline clusters which exhibit a dark caramel color & needle like, tabular crystals. Found inside the topaz crystals
3. At least a few individual crystals exhibiting a metallic sheen & truncated cube like crystalline structure. Found inside the topaz crystals

I have an educated guess for each of the unknown minerals listed below:
1. Epidote or diopside: not sure
2. Common topaz: somewhat sure
3. Galena: almost certain

I have added a few hazy but okay images showing the unknown very small minerals up close under (10x) or (40x) zoom.

If you have a clue regarding any of the mineral species involved please post your input. Replies regarding any thoughts about the inclusions are also more than welcome, thanks!

[Josele]

To my understanding, epidote, diopside and galena are not species that one expect to find in a pegmatite.
The green one, could not be elbaite?

[Bob Harman]

When diamonds are brought out of the mine, they go thru several steps before being brought to the buying public. The steps include being graded. Those doing the diamonds' grading, evaluate size, color, clarity, "fire" etc and whether there are inclusions of any size or type. Generally inclusions detract from each stone's overall "worthiness" to its jewelry value. All this has to do with the faceting of the stone to maximize its final appearance.

With colored gemstones used for jewelry it is similar. Inclusions are thought of as detrimental to the stone's jewelry value, both for its aesthetics and $$$ value.

While your's is a very nice collectible colored gemstone mineral specimen, for collectible minerals there are 2 types of inclusions. Those inclusions of a size and type that are aesthetically pleasing and worthy of study and display, and those very very small inclusions that are just considered imperfections in the stone, generally being not worthy of special note or display.
Having to use a 40x microscope to even see the tiny things, for me, says it all. Just a collector mineral specimen with microscopic inclusions of no special significance.
And as Josele notes, he is not at all sure what they are........Bob

[Riccardo Modanesi]

Hi to everybody!
Yes, it could be elbaite, but epidote crystals included in topaz are well-known. Another possibility is tiny ilmenite. Greetings from Italy by Riccardo.

[al mar]

I have seen elbaites directly associated with galena from brazil, and not glued for sure. Totally strange, but possible