Like frozen ocean water- Peruvian Blue Opal. A few of these are dendritic, meaning they have fabulous 'tree-like' inclusions that are usually the result of manganese oxides or silicates.
Difficult material to source
We are showing an example cabochon we had cut from this material for our Gem Dragon Auction
7 pieces / 103.28 grams / 14+ grams average
Estimate: $300 - $325