Benitoite is a very rare mineral worldwide and comes in gemstone quality only from California USA – Dallas Gem Mine and very little from the Junilla Mine a few miles away.
Discovered in 1907 and kept for sapphire, only a sporadic mining took place over the decades – as found only by a few miners and largely cut by them, this represents a rare stroke of luck in the world of gemstones. Sustainably mined, self-processed and marketed highly ethical Gemstone – comparable to Hauyn or the red Beryl.
Most of the stones are polished and often very pure. This counteracts the excellent optical properties such as high refraction, strong dispersion and a pronounced dichroism. Above all, colorless and lighter blue stones show this very pronounced.
Preferred shapes are the round brilliant – trilliants are visually very attractive – because of the rough stones often ovals, marquises and drops. Round stones are about 10-20% more expensive.
Small brilliants and small stones up to 0.25 ct are still sufficiently available. Starting at 0.5 ct, the price jumps per carat are getting bigger – from 1.00 ct doubled the carat price – 2-3 carats can already be five digits – there are no limits – an 8 carat stone was sold for $ 500,000.
Recommended stones are between 0.35-0.49 ct and 0.70-0.85 ct. Good optical size with better price / performance ratio.
Medium to deep blue (not too dark) are the most sought-after – lighter colors are slightly cheaper though very appealing. Colorless is very rare. By means of heat treatment, a secret procedure can only burn colorless stones in a delicate peachy to orange color. Many of the stones are destroyed during the treatment – therefore hardly available and extremely expensive (and beautiful!).
The cause of the color is not clear – most likely, the titanium contained in the stone is responsible. The mines are closed and renatured – little residual material comes from stock – the availability of certain sizes and shapes is severely limited. It is also increasingly easily smothered containing material.
A price-stable beautiful gemstone with outstanding properties.