What 'rocks/minerals'' are safe for Aquariums? I want to engrave an Ancient Greek inscription for tank (Interesting thread!)

[Mentat]

... I need help with the slate upon which I will write/carve the text. This material in question needs to be safe and clean for my aquarium. I was hoping that I would find help here on that particular issue.

I would go to nearest funerary and talk to person in charge of carved headstones. Think they could get you a thinner (headstones are thick and heavy) piece of granite or marble and carve it for you, or just sell you the stone and you can carve it yourself. Good luck !

[deranged chipmunk]

slate is fine to use. i have used italian slate from a defunct billiard table in my aquariums before with no issues. not sure where you would find it in your country though. limestone is a no no. it will release minerals into the water, making it very alkaline and hard. like carlos mentioned, marble and granite are ok. i would also stay away from sand stone. you can do a quick test on any rock for it's "usability". a couple drops of vinegar on the rock will do. if it fizzes and bubbles, don't use it

[Necromencer]

slate is fine to use. i have used italian slate from a defunct billiard table in my aquariums before with no issues. not sure where you would find it in your country though. limestone is a no no. it will release minerals into the water, making it very alkaline and hard. like carlos mentioned, marble and granite are ok. i would also stay away from sand stone. you can do a quick test on any rock for it's "usability". a couple drops of vinegar on the rock will do. if it fizzes and bubbles, don't use it

Excellent advice, this is exactly the information I needed. Limestone is used frequently in Greek epigraphy, so it's good to know that I should avoid it. I like the way you've given me the vinegar tip, that is excellent advice. I can actually start planning my project now.

And to Carlos, thanks for the tips, if I can't buy the material online, I'll go to a funerary and look there. I don't think I would have thought about that had I have not read your comment.

Excellent advice guys, I'll post a photo in the near future of the project.

[Dendro Dave]

Here is an old thread of mine on Dendroboard that touches on semi precious stone/mineral/metal safety (and possibilities!) a bit...
http://www.dendroboard.com/forum/par...struction.html

But one thing you can do with just about anything... is spray it down in clear plasti dip, or clear spray polyurethane (generally food safe in most forms once cured), both should be inert non toxic coatings when dry and which waterproof the material and prevent leaching of anything harmful.

Slate should work fine though.