I've had this black and green pendant stone for a while. Then I discovered onyx and then stumbled on magnasite. This onyx is matte polished which contrasts with the high polish of the black and green pendant. Its a texture thing. Magnasite is a mineral that is used in the manufacture of Epson salt (relaxing) and fireworks (exciting). You decide, relax in a tub or light a fire... or both... Its a beautiful necklace waiting for a neck to grace.