Mexican Opal 13-19mm faceted beads (ETB00434) Black Mop Thunderegg is not synonymous with

Thunderegg is not synonymous with either geode or agate

smallest bead : 12

B: 52x43x9

ranging from pale orange to an intense almost-black coloration

Dimensions of beads: (measurement is approx) 18mm(w)x31mm(h)x6mm(d) Length of this strand: 15

Mexican Opal 13-19mm faceted beads (ETB00434) Black Mop Thunderegg is not synonymous withMexican 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