Category: Gem Notes

Cuprite

INTRODUCTION Cuprite is a mineral species, cuprous oxide, with the formula Cu2O. It was named in 1845 by Wilhelm Karl von Haidinger. The name comes from the Latin “cuprum” in allusion to its composition. Cuprite is…

Vayrynenite

In the course of my 40+ year career in gemology, many gemstones have crossed my desk but rarely are they so special that they take your breath away. In the last year, this happened twice. The first time was with a 24 ct unheated padparadscha sapphire in a private collection.

Rhodonite

INTRODUCTION Rhodonite is a mineral species, manganese inosilicate, with the formula MnSiO3. It often contains minor Ca and traces of Mg and Fe. The name rhodonite comes from the Greek for “rose” (rhodos), in allusion to…

Diaspore

INTRODUCTION Diaspore is a mineral species with the formula, AlO(OH). It was first discovered in Sverdlovsk Oblast, Russia (the type locality) in 1801. Since the initial discovery, diaspore has been found in numerous localities around the…

Morganite (Natural or Treated?)

“Peach” is among the most desirable colors for gemstones. Whether it is sapphire, morganite or garnet…peach is hot! The Pantone Color of the Year for 2019 is “Living Coral” so the color peach is even…

Johachidolite

INTRODUCTION Johachidolite is a very rare mineral of a borate group. Thismineral was first discovered by Japanese scientists E. Iwase and N. Saito in 1942 in the territory of occupiedKorea, in a place that in the…

Tenebrescent Zircon

Zircon is a well-known gemstone that is available in a variety of colors from many worldwide locations. Not very well-known is the variety known as tenebrescent zircon. Tenebrescence, also known as reversible photochromism, is defined as…

Hiddenite

Spodumene that is green in color is often sold under the name “hiddenite.” In the strictest sense, the term hiddenite refers to pale green to emerald green transparent spodumene colored by chromium from Alexander County…