Gregtech 4 incorrectly classifies Granite from both Et Futurum and Botania, and possibly other mods that backport it, as ore:stoneBlackGranite, despite not being black. I am unsure if this is a balance issue at all, but because it's "black granite", it could possibly used in place of actual Black Granite in the production of Biotite Dust and Stainless Steel.