raw specimen gabbro with quartz vein stone on white background.

allotriomorphic apparent background banding black carbon coal coarsegrained cooling crystal crystallization distinct earths formed fossil gabbro gabbros geology gneiss gold granite hand intrusive iron isolated macro mafic magma material metal metamorphic mica microscopic mineral molten natural nature nugget ore plutonic pyrite quartz raw rock rocks rough sample scale specimen stone surface texture trapped vein white