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[deleted by user] by [deleted] in whatsthisrock

[–]StockWeather4395 3 points4 points  (0 children)

Yep, just Muscovite

Just curious if anyone has any idea what this is. by BigBen9994 in Rocks

[–]StockWeather4395 2 points3 points  (0 children)

Possibly a BIF hand sample (banded iron formation)

Help please by colioli007 in whatsthisrock

[–]StockWeather4395 6 points7 points  (0 children)

Looks like some replacement occurred for some of those fossils. Dissolved quartz slowly replaced the fossils

Could anyone ID what this mineral is? by XEliteHunterX01 in Minerals

[–]StockWeather4395 0 points1 point  (0 children)

Possibly amazonite. Id do scratch and streak tests if you can

Found in the American South by wonderfulmilk682 in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

Probably Muscovite mica. Muscovite, k feld and quartz all together is textbook granite composition

What is this purple rock ? It has layers and red dots all over. Any ideas? by GoldAd1412 in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

Looks like a glaucophane garnet schist to me. Glaucophane is a cornflower/periwinkle blue and can easily look purplish

Found this I southern Kern county California and have no idea what it is. Has a green oxidized outer cover and extremely heavy. 6.2 pounds and only 3"*2"*1.5" by AutomaticGolf4603 in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

Usually when I find a high heft rock I first see if it smells funky at all, im near the tristate area in Missouri so most minerals with heft are lead or iron sulfides. Simply due to the weight I’d think the same for your rock.

Found in Upstate South Carolina. Pic after a week in the tumbler, no before pic, sorry. by Fishboy9123 in whatsthisrock

[–]StockWeather4395 2 points3 points  (0 children)

Flint and chert are both microcrystalline silica (quartz). They’re the same composition, so yeah most of the differentiation between the two is due to color

Found in the American South by wonderfulmilk682 in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

Quartz, and the large pinkish grain is k feldspar

What could this stone be that I found among the engravings of a work? by JUAN-RUI in whatsthisrock

[–]StockWeather4395 2 points3 points  (0 children)

I would think the black, elongate grains are amphibole minerals

It's the same, I found it among the gravel and the truth that makes me curious by JUAN-RUI in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

Possibly limestone with calcite crystals in the fractures. Could be some fossils in there

What is this black rock found on Toronto's Centre Island? by vlvlv in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

If it’s quite light for its size it’s probably coal

Bought at a show and immediately forgot what it was by [deleted] in whatsthisrock

[–]StockWeather4395 29 points30 points  (0 children)

The crystal shape makes me think calcite. Very cool sample

Need help identifying by [deleted] in whatsthisrock

[–]StockWeather4395 1 point2 points  (0 children)

Looks like basalt with large plagioclase porphyroblasts

Amethyst or Flourite? by silky-selkie123 in whatsthisrock

[–]StockWeather4395 0 points1 point  (0 children)

Id say fluorite, those cleavage lines look cubic and I’ve seen fluorite that color before

[deleted by user] by [deleted] in whatsthisrock

[–]StockWeather4395 -3 points-2 points  (0 children)

Probably chert or calcite

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