🏢🌋 Stone 🗿🏛️ on Instagram: "I keep hearing “black granite”, but there’s no such rock. What people are actually looking at are dark igneous rocks like gabbro, norite, dolerite or basalt, none of which are granite in geological terms. Granite is light-coloured, quartz-rich and felsic; these are mafic rocks with completely different mineralogy and origins. I also touch on the story of Rustenburg Stone from South Africa, which slipped through apartheid-era sanctions by being marketed as “Zimbabw