Lucy

These rocks came with a used aquarium I bought.
Any ideas what they are or a little about them?



Thanks!

CoryMac

the 2 bottom rocks are "Crystal meth" rocks, for sure no doubt,lol just kidding..I have no idea, but the are are very pretty rocks, top right almost look like some jade in there, but what am i to know.

prairielilly

Ooo! rocks! I like! Three of them are definitely chunks of quartz. The upper right one (funny green-pink one) I really don't know - could also be quartz, could be something else. Could you post a closeup of that one rock?

Quartz = silica, about as inert as you can get under normal conditions. Most plentiful mineral on earth. Very hard, very low chance of dissolution/disintegration (it's crystalline) or of shattering/breaking/hurting your fishies.

coffeebean

definitely quartz. the green may be some mica?

prairielilly

wrong cleavages and lustre. I thought possibly an amphibole but I'd need to see it closer. It's not the right lustre for malachite either. Lucy I don't suppose you have any dilute acid around?

Lucy

Thanks! Here's a close up of the one with the green on/in it.
Ooops, missed part of it in this shot. lol

prairielilly

Quartz, quartz, quartz...

Lucy

Thanks bunches, the green is quartz also? All safe then?
Had to google dilute acid, nope none of that lying around. lol

I'm not sure I'll use them for the aquarium I'm setting up but good to know I can when I want.

prairielilly

All safe Yes it's all quartz I'm as sure as I can be w/o touching it. Silica can dissolve under certain circumstances, but I think it's highly unlikely in the average aquarium (requires very acidic conditions) and if any did, it would be minimal and not harmful to fish (might promote some algae). If I had to pick a particular mineral as safe to put in an aquarium, I'd pick that one.

That was great! do you have any more rocks?

Lucy

No, those 4 came with the aquarium. I have a pretty cool purple one in my frog tank. I have no idea what it is or where I got it. It was just kind of hanging around the house. lol
I'll take a pic. and post it.

CHoffman

Glad it's not pyrite Lucy!!..ROFL

coffeebean

oh wow. the green is fabulous on close up. beautiful rock!!

Lucy

Me too!

Thanks

Here's the purplish one from the frog tank.

A couple different angles. I really like this one.

prairielilly

Lucy I had another look at the pink/green rock and I still think the green/brown is quartz, but the pink stuff may be feldspar. Hard to tell without holding/scratching it/looking at it w. magnification. Doesn't matter really - feldspar is safe too (most ceramics are made from it).

Pretty decent bet the purply rock is also quartz, judging by the way it's fractured (like glass breaks - we call it conchoidal fracture). We use silica to make glass...Pretty isn't it? amethyst purple! Perfect crystals that colour would make real nice jewelry

Thanks for letting me play with your rocks I enjoyed that!

Lucy

I enjoyed learning about them, thank you!