Quartz
Hanson Stone Quarry, Rougemont, Durham County, North Carolina, USA
The tip of a rock crystal with a nice striated s-face { 1 1 -2 1 }. The s faces can sometimes be used to determine the handedness of a crystal. Their position relative to the rhombohedral faces will indicate the handedness, if they are right of the positive rhombohedral face, the crystals are right-handed. The problem is to distinguish positive ...
© Amir Akhavan