Uvarovite is the calcium chromium member of the garnet group and the only common garnet that is always green. Its crystals are bright emerald green but almost always tiny, often less than a few millimeters across. Instead of being faceted, uvarovite is usually set as a druzy: a crust of glittering crystals still attached to the rock. The Ural Mountains of Russia are its classic source.
What uvarovite is
Uvarovite's ideal formula is Ca3Cr2(SiO4)3, with calcium in the X site and chromium in the Y site. It belongs to the ugrandite series of garnets, along with grossular and andradite, and natural crystals usually contain some of both. Chromium gives uvarovite its intense green, the same element that colors emerald and ruby. The color in gemstones page explains chromium as a chromophore.
The mineral was described in 1832 from the Ural Mountains and named after Count Sergei Uvarov, a Russian statesman and president of the St. Petersburg Academy of Sciences.
Uvarovite is cubic and singly refractive. Its refractive index is high, about 1.86, and its luster bright. Hardness falls around 6.5 to 7.5 and it has no cleavage. Crystals are usually well-formed dodecahedrons, sometimes with modified faces, and they sparkle strongly in light because each small face acts as a mirror.
Why uvarovite crystals stay small
Uvarovite forms where chromium is available in calcium-rich settings. Chromium is concentrated in chromite, a black oxide mineral found in ultramafic rocks such as serpentinite and peridotite. Uvarovite crystallizes in thin veins and fractures in and near chromite deposits, from fluids carrying calcium and chromium. These spaces are narrow and the supply of chromium in the fluid is limited, so crystals stay small and grow side by side in crusts rather than as large single crystals.
Facetable uvarovite is extremely rare. A few cut stones weighing well under a carat exist in collections, and they are curiosities. The crystal habit page describes druzy and other crystal habits.
Sources
Russia
The Ural Mountains are the classic locality. Uvarovite occurs with chromite near Sarany, in the Perm region, and around other chromite mines in the Urals. Russian material forms dense crusts of bright green crystals on dark chromite or on white to cream host rock, and it is the source of most druzy uvarovite in jewelry.
Other sources
Uvarovite has also been found in Finland (Outokumpu), Turkey, Norway, South Africa, Canada (Quebec), the United States (California and Pennsylvania), Spain, Italy, India and Japan. Finnish crystals from Outokumpu are among the largest and best formed for the species, though still small by gem standards.
Uvarovite in druzy jewelry
Druzy, or drusy, describes a surface covered in many tiny crystals. In jewelry, druzy uvarovite is cut as a slab or cabochon-shaped piece of host rock with the crystal crust facing up. Jewelers set it in pendants, earrings and rings, often in bezel settings that protect the edges. The crust sparkles like green glitter, and no two pieces look the same. The druzy page covers druzy jewelry of all kinds, including quartz and agate druzy.
Natural uvarovite druzy is not coated or dyed in most cases, because its natural green is already intense. This sets it apart from much druzy quartz, which is often coated with metal films to give it color. Buyers should still ask, because coated imitations of green druzy exist. The gemstone treatments explained page covers coatings.
Identification
Druzy uvarovite is easy to identify by its bright emerald green, tiny dodecahedral crystals and sparkling crust. Possible confusions include green-coated quartz druzy, which may show uneven color or wear on high points, and fine-grained green minerals such as chrome-bearing micas or chlorite, which lack the sharp crystal faces. Under magnification, uvarovite crystals show many-sided garnet forms. A Chelsea filter may show red because of the chromium. The gemological instruments page describes these tools.
Uvarovite is sometimes confused with green grossular or demantoid, which can also be colored by chromium. Those form larger crystals and are faceted. See grossular garnet and andradite garnet for comparison.
Wear and care
Druzy is more delicate than a polished stone. Individual crystals are hard, but the crust can be damaged if knocked or rubbed, and snag-prone points can catch on fabric. Druzy uvarovite suits pendants and earrings best. In rings, choose a bezel setting with a raised rim and wear with care.
Cleaning needs a gentle hand. Rinse with lukewarm water and mild soap, and use a very soft brush only if needed, working lightly. Do not use ultrasonic or steam cleaners, which can loosen crystals or damage the host rock. Dry gently and store apart from other jewelry so harder gems do not scrape the crust. The jewelry cleaning guide has general advice.
Value
Uvarovite is a collector mineral and a niche jewelry material. Value depends on the brightness and density of the crystal crust, the size of individual crystals, and the attractiveness of the host rock. Specimens with larger, sharp crystals are prized by mineral collectors. Jewelry pieces are generally moderately priced. Because every crust is different, buyers usually judge each piece by eye, looking for even coverage, strong green color and no bare or crushed patches.
Frequently asked questions
Can uvarovite be faceted?
Rarely. Uvarovite crystals are usually too small to facet, and the few cut stones that exist are tiny collector curiosities.
Why is uvarovite green?
Chromium is part of uvarovite's chemistry. It is the same element that colors emerald, and it gives the garnet an intense green.
Is druzy uvarovite durable?
The crystals are hard, but the crust can be scraped or chipped. It suits pendants and earrings better than rings worn daily.
Is uvarovite a January birthstone?
Uvarovite is a garnet, and garnet is the January birthstone, so it qualifies. Most January jewelry uses red garnet, which makes green uvarovite druzy an unusual choice for the month.
Where does uvarovite come from?
The Ural Mountains of Russia are the classic source. Finland, Turkey, Canada and other countries have also produced it.