Quartz (Japan Law twin) - Wegner Quartz Crystal Mines, USA - specimen is 6.5 cm, largest quartz crystals are 2.5 cm

Mineral: Quartz (Japan Law twin)
Locality: Wegner Quartz Crystal Mines, Mount Ida, Montgomery County, Arkansas, USA
Dimensions: specimen is 6.5 cm, largest quartz crystals are 2.5 cm

Description: Clay or shale inclusions in quartz. So called blue phantom quartz.The 2 largest crystals are an example of Japan Law twinning.