Small World Slate & Stone is proud to offer these beautiful natural slate stones. They are safe for use in your scenery and will not Small World Slate & Stone is proud to offer these natural slate stones. They have been sourced, washed, hand picked, and packaged by a family owned business in the USA. They are safe to use in your scenery and will not deteriorate. Perfect for Aquariums and Reptile enclosures. Create caves, cliffs, basking areas, berms, water falls and walls in your aquarium, terrarium, paludarium, vivarium or miniature garden. These stones are easy to incorporate into your tank or enclosure and pair beautifully with our smaller and larger stones and gravel to give a more realistic look to your tank. Thoroughly rinse all stones before placing in your habitat. Absolutely no coatings on this or any of our stone. Slate is inert and aquarium safe. Any quartz veining on the stone may have a small amount of carbonate minerals which can raise/buffer pH