New Mexico Mineral Symposium — Abstracts

The California Blue mine is a recently discovered beryllium-fluorine miarolitic pegmatitic granite intrusion located in the Mojave Desert, California. The claim is located in San Bernardino County near Yucca Valley. The dike is fairly simple, being composed predominantly of quartz, perthite and albite. There is minor light and dark mica, especially associated with the cavities. The beryl crystals occur in close association with the cavities, similar to the micas. Gem aquamarine is found within the cavities growing from their walls, perched on terminated quartz or feldspar crystals or as euhedral “floater” crystals. Replacement gem crystals are also found outside of the cavities as irregular etched looking crystals after earlier heavily included crystals.

The miarolitic cavities occur centrally within the intrusion as two general types: quartz, perthite and albite and quartz, 2 feldspar, white mice, aquamarine +/- topaz. The bimodal nature of pockets is favored by the morphology of the dike, which is a tabular body with meter scale sub-verticle apophyses. Cavity formed aquamarine occurs within the tabular portion of the dike only. The apophyses contain cavities with quartz, microcline and albite, but no aquamarine.

The claim was discovered in 2006 and mined by hand until 2010 when a partnership was formed to mine for aquamarine using large machinery. Currently the claim is being worked intermittently in open-pit style mining and continued specimen production is expected