Faceted Blue Spinel Gemstones, Soviet Gem expensive These labgrown sapphires have bubbles

These labgrown sapphires have bubbles in them from the growth process -- we call this variety 'strawberry sapphires' since they have seeds

This one measures 30x38mm and weighs in at 81g

but the stones had too many rainbows and were obviously something different

They are tan out of the ground and have to be treated to get a darker background

Its high hardness (8

Faceted Blue Spinel Gemstones, Soviet Gem expensive These labgrown sapphires have bubblesThese are blue gems cut from old stock flame fusion spinel grown in the Soviet Union, sourced from an old collection The color intensity and darkness varies considerably from stone to stone, each is photographed individually. Blue Spinel is typically colored by cobalt, which gives it a red fluorescence with strengh varying based on cobalt concentration and codopant types. While this material is grown with the flame fusion method, in industry