DG0001 : 5.12ct Moss Green Demantoid Garnet – 10mm

VALUE

Demantoid Garnet is one of the rarest garnet varieties. It can be found in a green color vibrant enough to rival emeralds. They are highly prized stones for gem collectors, jewelers and jewelry enthusiasts.

Despite the discovery of new sources of Demantoid during the 1990’s the stone still remains very rare. Is it the most valuable of the garnet family as well as the most well-known andradite garnet. A clean facetable stone can command a high price per carat. However, the stones collectors seek out the most are demantoids with horsetail inclusions, wavy golden and fibrous inclusion.

INFORMATION

Demantoid was discovered in Russia in the early 19th century. In 1854, mineralogist Nils Gustaf Nordenskiöld recognized this gemstone as a variety of Andradite garnet. The gemstones had exceptional brilliance and a dispersion which inspired the mineralogist to name them after their ‘diamond-like’ appearance, giving birth to the name Demantoid.

The truth is that demantoids have greater brilliance and a higher dispersion than diamond as well as other well-known green gemstones, like emerald and peridot for example. The dark colors of their body may mask dispersion, smaller demantoids with lighter colors and hues are dazzling under natural light.

The gemstone was very popular during the Belle Époque period of the late 19^th and early 20^th centuries. It was most popular in Art Nouveau jewelry and was highly favored by the Russian Czars.

For a long period of time, Russia was the only source for these garnets. Supplies soon began to run low and the gems were usually only seen in antique pieces of jewelry. However, since the 1990’s sources have been discovered in Namibia, Madagascar and other sites. The Russian mining has also been renewed and Demantoid Garnet are available again today. However, in the modern-day market, they are expensive stones because they are highly desirable.

Charecteristics : horse tail

Horsetail inclusions of byssolite or chrysotile, usually with a golden color, obtain their name because of their long, wavy appearance. These inclusions have long been considered diagnostic for identifying demantoids. However, a study in 2018, found horsetail inclusions in non-demantoid (brown) andradite. Thus, while horsetails are a good identifying characteristic, it isn’t sufficient, as other stones also have horsetail inclusions and not all demantoids have them.

Demantoids may looks similar to emeralds in color and appearance, however, the optical and physical properties of both stones differ greatly. Demantoids have greater dispersion and no birefringence.

SOURCE

As we mentioned earlier, Russia was the only source for demantoids for a long time. Notable gem sources include the Ural Mountains region, the Koryakskoe plateau, and the Kola Peninsula.

Since 1996 and 2009, respectively, Namibia and Madagascar have become important sources.

In Italy, Ala, Piedmont produces dark, apple-green material. Val Malenco, Sondrio Province also produces demantoid.

Other notable sources include:

• Russia
• Africa

CARE

Demantoids should be cleaned using warm soapy water and a soft brush. Avoid all mechanical cleaning and exposing your stone to extreme heat.

Some demantoids may have a hardness of 7.5, which means they are somewhat susceptible to scratching. Therefore, use protective settings for these gems, especially if used as ring stones.