These are lab grown green to blue-green sapphire doped with cobalt.
This is flame fusion-grown cobalt doped sapphire--a little outside my normal wheelhouse but I made an exception for this material. Cobalt isn't known to color sapphires in nature, but in lab-grown stones it can give a vivid, pure green or a rich blue-green. However it is also poorly behaved, and stones are unpredictable, with a range of colors even within the same crystal, and many also have tiny vivid blue inclusions of cobalt aluminate (cobalt spinel). They also tend to be very cracked up, and I had to spend a good amount of time trimming these clean. These are worth the trouble, with an absolutely amazing range of colors.
