Photo category: Rocks and Minerals specimen collection
- Photo taken Locality: Tunisia
- Photo taken by: Trichas, A.
- Photo taken date: October 2011
Photo of a sample of geoid Quartz, bought in Tunis in 1997. Outside, each geoid looks like as a moderate-sized stone and inside the cavity is covered with quartz crystals and many small shimmering. It has a vitreous luster and the color is yellow to white-yellow. It has hardness of 7.