Boulder Opal 14mm Beaded Necklace, 19 Inches

Details

Description

The necklace is 19 inches (48 cm) long, and the smooth round beads are 14mm in size.
Boulder opals come … Read more The necklace is 19 inches (48 cm) long, and the smooth round beads are 14mm in size.
Boulder opals come from Andamooka, South Australia, sometimes called “painted lady.” Boulder opal matrix may be brown, gray, orange, or white. If the matrix is dark, the stones are known as “boulder blacks.” Opal play of color is caused by light diffraction induced by organized silica spheres within the precious opal.
The necklace is fastened with a very comfortable sterling silver clasp with an opal cabochon.
Bead knotting is traditionally done with silk thread. A knot is placed between each bead to prevent them from rubbing against each other.
The weight of the necklace is 130 grams (4.6 oz).

Boulder opals are easily distinguished by their layer of solid brown ironstone left on the back of the stone. As the name suggests, Boulder opals are mined from large ironstone boulders under the ground. Thin veins of colorful opal form in cracks and fissures in these boulders.

In South Australia, Opal was first discovered in Andamooka in the 1930s. Sam Brookes and Roy Sheppard discovered the first Andamooka Opal. Caught in a thunderstorm, they sheltered under a tree when a pretty rock caught the corner of their eye. Smaller deposits were exposed afterwards including Lambina during 1930 and Stuart Creek in 1947. Opal at Andamooka exists in the thin marine ‘Bulldog Shale’ which is the significant portion of the Marree Subgroup of the Early Cretaceous period. See less