Lavender Rough Opal Pieces - While Supplies Last

Hi Terry,

It's like the crust on a slice of bread. Were you one of those kids who made his mom trim the crust off your sandwiches? Haha!

Here are two explanations for the dark layer on the opal top of the opal slabs, as shown on some of the pieces in the photos on our website.

1. The Crucible Edges
Premium lab-grown opals take roughly 10 to 18 months to grow in a highly-controlled laboratory environment. Sub-micron silica spheres are settled or chemically grown inside a mold or crucible container. The outer 'skin' is the zone where the chemical mixture made direct contact with the walls of the container during the settling, compression, or heating phases. Just like bread dough touching a hot baking pan, this outer boundary cures with a different texture and look than the pristine, colorful interior.

2. Settling and Excess Resin Pools
Most ultra-premium, thick synthetic slabs are polymer-impregnated opals consisting of roughly 80% silica and 20% resin. During the stabilization process, the porous column structures of silica are soaked in a chemical resin to prevent cracking or crazing. Excess resin naturally pools, settles, and hardens on the outermost top, bottom, and side faces of the massive slab block. This creates a thick, dark, dull, or uneven plastic-like crust over the opal layers underneath.

Best,

Carolyn
PAS Support