Orbicular Jasper (RARE California) Ken Roberts Coll.

Item Description

Orbicular jasper is RARE from any of the numerous California localities, that MINDAT lists, except from this obscure locality in Santa Clara County. Fantastic, colorful, multi-hued banded orbs and matrix cover all sides of this surreal, sliced and unpolished section. The reds, tans, yellows, greens and grays in the orbs and matrix are absolutely striking. Orbicular Jasper is a name given to a highly silicified rhyolite or tuff that has quartz and feldspar crystallized into radial aggregates of needle-like crystals forming orbicular (spherical) structures (MINDAT). 10 4-mm slabs of diminishing size could be cut from this fine old rarity. Probably collected in the 1950s. From the Ken Roberts Collection. 439 grams mass.