Petroleum Quartz (Quartz with Petroleum, Methane, Bitumen, and Water)

Being a particular kind of enhydro , doubly terminated quartz crystals containing negative crystals filled with petroleum, methane, bitumen, and water, are rare, though material of very good quality appears on gem and mineral fairs on a regular basis. Under ultra-violet radiation the petroleum inclusions present in the material reveal a strong fluorescent reaction.

This most striking material originates from the Zhob District in Balochistan Province, Pakistan, although some time ago one dealer had material on offer unearthed in the Jihouke District, Leshan Prefecture, Sichuan Province, China. However, these samples contained quite some bituminous matter, but far less petroleum and resemble herkimers with anthraxolite from the Adirondack Mountains in New York.

It might be interesting to note that petroleum inclusions similar to those in Pakistani quartz have also been found in quartz crystals originating from Bahia, Brazil (Gübelin & Koivula, 2005).