Category: Gem Notes

Unusual Diamond Crystal

An old European cut diamond in a ring setting came in for an appraisal. The approximate measurements were 5.00 x 4.90 x 2.59 with an estimated weight of .39 cts. At first observation, the diamond…

Glass Filled Ruby

While much has been written about glass filled ruby and its sudden surge of presence in the marketplace and ease of identification, little has been written regarding the instability of this material. About a year…

Diamond Flash Effect

Two years ago, we wrote about the distinct difference between natural strain in a diamond and the flash effect seen in glass-filled diamonds. Mostly, separation of the two should be easy, yet we have seen…

Cassiterite

Recently, a client brought in a small assortment of gemstones to our lab and represented them to be crystallized tin from Bolivia. His initial excitement came in the hopes that this would prove to be…

Largest Tsavorite Found

This tsavorite was exhibited in Tucson at the gem show. Weighing 325.13 carats, it is reported to be the largest tsavorite ever cut. According to Michael Couch & Associates, the stone was found in the…

Fancy Pink Diamond?

Recently we examined a custom-made ring that contained a cushion cut center diamond surrounded by 28 round fancy pink melee. The ring also contained other round brilliants in the setting. We estimated the center diamond…

Natural Yellow Sapphire

Recently a subscriber submitted a cushion cut yellow sapphire weighing 5.13 carats for an estimate of wholesale value. The stone exhibited a fairly even yellow color consistent with GIA GemSet Y4/5. Our initial examination was…