The colored gravel is color epoxy coated real rocks. <At least the package I had years ago said epoxy coated!>
says epoxy coated right on the package...
Some of the "gravels" are colored glass or ceramics. These have the advantage of not having the coating flaked off.
And I am changing the title so you guys won't get confused!!!
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.