These are cabochons cut from titanium laser sapphire. These labgrown sapphires have bubbles in them from the growth process -- we call this variety 'strawberry sapphires' since they have seeds, hence the carvings. The bubbles have a directional flow to them, following the movement of the sapphire melt during crysatllization, and many are deep blue-black due to iron contamination.
Titanium sapphire is a very unusual variety of sapphire, never found in nature. Because even a few parts per million of iron will interact with titanium ions and produce a dark blue, there's nowhere on Earth a crystal like this could grow naturally.
In fact, the purity required is so high that titanium sapphire doesn't get grown with cheaper lab methods either - flame fusion setups have a hard time obtaining the extreme chemical purity needed for pink titanium sapphire.
When it's grown with industrial purity, however, however, the resulting crystal is a bright padparascha-like pink color which shifts between a starburst pink and a more pink-orange depending on the lighting. We were able to get some leftover offcuts from a laser crystal grower--these were not produced for the gem trade but they make for incredible gems.
With a hardness of 9 sapphire is ideal for use in all kinds of jewelry.
