Mexican Opal 13-19mm faceted beads (ETB00434) Black Mop Bryozoan Coral 13-14mm round beads

Bryozoan Coral 13-14mm round beads (ETB00887)

Size: 10 - 12 mm

Cacoxenite Amethyst

often associated with Native Copper

Mexican Opal 13-19mm faceted beads (ETB00434) Black Mop Bryozoan Coral 13-14mm round beadsMexican Opal Cantera opal These stones are comparable to Australian boulder opal and its origins are similar. These are found as small pockets or seams veins of opal associated with rhyolite matrix, the host rock, which is softer than the opal. The word cantera refers to the host matrix. Like boulder opal and koroit opal, these stones were not initially as prized as the pure cuts but cutters and buyers of both koroit boulder and cantera opal came to