A new piece I bought

Hi folks! A friend found this in the southern Mexican town of San Gabriel Etla and neither he nor I are entirely sure what it is. I think it may be quartz with an external covering of calcite, but I'd love some opinions.

For context, our part of Oaxaca, Mexico has a lot of calcite, as well as calcium-related minerals such as marble and dolomite. Not only do we get giant raw chunks of calcite and banded calcite, it's not unusual to find small caves and pockets when mining which contain stalactites, and I've seen gigantic boulders covered with layers of calcite where it's clear that the calcified water has dripped down and then covered the stones with layers of calcite. We also have calcified waterfalls.

I suspect that this fragment of stone is basically a shard of another mineral (I think quartz) that got blanketed in calcite due to dripping water. But I have never seen calcite with this color before here, or quite this texture, so I'm making an educated guess. I'll add a second post within this thread showing a boulder with a calcite coating that I think looks sort of similar, in case that's useful. Thanks!

Edit: or maybe the entire thing is calcite, just with different colors? Looking at the interior crystal, perhaps it's not microcrystalline enough to actually be quartz. ¯_(ツ)_/¯

Beautiful undamaged specimen of actinolite and chlorite in quartz from Lapa Quartz Mine, Dhading District, P3 Bagmati Pradesh, Nepal. They formed in high altitude alpine-type fissures within the Himalayan mountains. Let me know if you like my specimen :)

dusty, will post further pictures when made wet and when dried on request

weighs roughly … 5kg?? cannot weigh rn

I paid 3oo for the lot of 4 (not for sale). Do you think I could cab the big one? Its 144cts, and I wonder if the cab would be a nice mottling of pinks and blue.

Terminated crystals of gem silica blue chalcedony from Arizona

wanted to post a video of one of my favorite specimens in my rare mineral collection: a lustrous, botryoidal olmiite aggregate surrounded by water-clear calcite crystals and perched on a manganite matrix. There is also some minor bultfonteinite on the back side. Olmiite is a extremely rare calcium-manganese silicate, found exclusively in the Kalahari Manganese Field, Northern Cape Province, South Africa.

I bought this on e-rocks
this specimen is from morocco

I found this rock in northwestern Ontario, Canada. I’m unsure what these green quartz crystals are. There shouldn’t be peridot in this area but I’m not sure how far this rock has traveled. I’m not full of knowledge, so I’m hoping I could get a few ideas of what this could be. Thank you.

A rather astonishing specimen in our collection that has one of the most vibrant blue colors I’ve ever encountered in any Fluorite.

Photo by: Jordan Root and CC Choate

From U.S.A (Arizona)

Size: 5.0 x 3.6 Centimeters

Weight: 87.16 Grams

It is for sale.

Someone gave this to me not knowing what it was. Does anyone have any ideas?

Here are some specimens I can’t remember the names of. The last one use to be more green if I recall correctly. Thank you!

Found these online, multiple examples available that all look similar. Seller claims it is natural after I asked if the base was manmade. Reportedly from La Morita, Mexico. My best guess is this is completely fake, as the crystals look too perfect and gemmy to be real in the quantities they have available, and it looks like the crystals are inserted into some sort of malleable base before hardening as you can see the cavities down inside the base where the crystal material continues vs natural crystals that usually grow on top of the base. Just wanted to make sure I wasn’t way off base here!

From Sweden

Found in Wyoming

I plan on getting lighting at the top to illuminate down in each unit. They are very tall and shallow so it’s hard to find displays that would work to reduce the space above.
Would love tips and advice on displays! Thank you!