Last 3000 years, In Tibet Himalaya , Xinjian province China ,Southern Asia, India Peninsula, Persian regions, local people found thousands small but rare and strange agate rocks, solid,  inner rock comes with very mastery fine grain called Sardonyx (缠丝玛瑙), which believe were fossils of torched / melted Bio-grain of tree, weeds, tusks, shells, etc. And they were fabricated as beads, balls, tubes, to be trade beads, jewelry beads, amulet beads, personal and tribal Identity beads. All those mastery grain agate, They difference than earth quick and volcano--- with high pressured underground, water steam involved, anti-gravity from deep earth to surface of earth, Instead of , much more believable, they were torched and melted by much higher temperature meteorite from space, by gravity dropping, drilling, burning,  melting..... Finally became Sardonyx fossil as we see after artist polished. And most attractive of them were turned into "Eyed"  amulets as we see today, called "Natural DZI beads ".