Amethyst

[Alfie McCloy]

Weird question, has anyone ever put an amethyst geode in their tank?

 

[Daniel@R2R]

Weird question, has anyone ever put an amethyst geode in their tank?

I'd wonder about chemistry issues. @Randy Holmes-Farley or one of our other #chemistrygurus may know

 

[jcolliii]

The amethyst itself will be inert, but the rock that houses the geode maybe not so much. Geodes that weather out of volcanic rocks may be fairly safe as the pore space around the geode has likely been infilled by microcrystalline quartz - which is why it weathers out of it's host rock and is then pretty resistant to further weathering. BUT... if the geodes are cut out of igneous rocks, the remaining rock - especially volcanic rocks - will contain minerals with abundant iron and aluminum. The aluminum is bonded with silicates in various feldspars which can break down to clay minerals faster than you might think - and that can liberate some aluminum. Under the right set of temperature, surface orientation, vegetation cover, and precip conditions, I've seen granite (mostly feldspar) weather from rock to grus/clay at a rate of approximately an inch per year. Not sure how much aluminum is released/dissolved though.