I have a lot more rocks than this, but these were the ones that were displayed in the first place!

My yellow and purple sections are thin, so any minerals suggestions would be appreciated!

Arizona "Gem silica" chrysacolla infused chalcedony

I had 2 of the extra slabs I have polished on one side for display and a gift

It looks like glass, but it also has small pink rocks inside. What is it?

1) Cobaltocalcite & kolwezite DR Congo
2) Aurichalcite 79 Mine, Arizona
3) Galena Sweetwater mine, Missouri
4) Olmiite & calcite N,Chwaning mine, South Africa
5) crystalized Pink Quartz Minas Gerais, Brazil
6) Olmiite N’Chwaning Mine, South Africa
7) Mimetite Chihuahua, Mexico
8) Sphalerite & Quartz Smolyan, Bulgaria
9) Chrysocolla tentadora Mine, Peru
10) Barite Linwood Mine, Iowa
11) Prehnite O&G Quarry, Connecticut
12) Vanadinite & Calcite La Paz, Arizona
13) Fluorite Erongo Mts, Namibia
14) Chalcopyrite & Dolomite Missouri, USA
15) Quartz Var. Amethyst Tutu cliffs, Nigeria
16) Amazonite feldspar Teller County, Colorado
17) Calcite N,Chwaning Mine, South Africa
18) Quartz Var. Amethyst Streep mine, Namibia
19) Calcite & Marcasite Linwood Mine, Iowa
20) Amethyst with Hematite South Africa

I’m gonna call it UCO unidentified crystal object.. lol

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)_/¯

A new piece I bought

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.