Rock Crystal Smoky Quartz Double Terminated Crystal Point

A polished rock crystal and smoky quartz double-terminated point with two termination axes growing from a common base. Clear rock crystal areas and smoky quartz-tinted phases alternate.

The double termination emerges from a common root point. Two crystal axes form upwards, either parallel or at a slight acute angle. This is a rarer growth form than the usual single termination.

Rock crystal and smoky quartz both belong to the quartz family. The transition from clear to smoky documents a zonal change in the surrounding pegmatite. Phases without radiation produced clear growth, while phases with aluminum impurities and radiation led to smoky quartz-tinted areas.

What distinguishes this point is the fluid transitional zone between the two mineral phases, without a sharp demarcation line between rock crystal and smoky quartz.

A collector's item with didactic value: two quartz varieties in a single crystal.