Gem-quality chrome diopside and violane are mined in limited amounts in Siberia, Russia. Most of the chrome diopside used in jewelry today comes from a few locations in Siberia. Small occurrences of chrome diopside are also known in Austria, Brazil, Burma, Canada (Ontario and Quebec), Finland, India, Italy, Madagascar, Pakistan, South Africa, Sri Lanka, and…

Diopside has potential uses in ceramics, glass-making, biomaterials, nuclear waste immobilization, and fuel cell technology. Unfortunately, natural diopside is rarely found in deposits that simultaneously have a size, purity, and location that allows economic mining. This makes synthetic diopside cost-competitive with diopside produced by mining.

Some diopside that was formed during the contact metamorphism of dolomite or limestone has a granular texture similar to marble. This material is known as “violane.” It is often white, gray, light blue, lilac, or purple in color. Violane accepts a bright polish and is sometimes used to make cabochons, beads, and ornamental items. Violane is…

Some diopside crystals are filled with microscopic needle-shaped inclusions that occur in a parallel alignment through the crystal structure of the mineral. This network of parallel inclusions is known as a “silk.” When this diopside is cut en cabochon, the parallel needles of the silk can reflect light much like how light is reflected from…

Some crystals of diopside contain enough chromium to give them a rich green color. These can be cut into beautiful faceted stones, beads, and cabochons. The appearance of these stones is best when they are under two carats because the material is often dark or strongly saturated. Chrome diopside is occasionally seen in commercial jewelry. It has…

Most diamonds found at or near Earth’s surface were delivered from the mantle during deep-source volcanic eruptions. These diamonds occur in vertical igneous structures known as pipes, which are often composed of kimberlite or peridotite. These pipes are difficult to locate. Their surface exposure is usually covered with soil and vegetation, and it might be…

The most common occurrence of diopside at Earth’s surface is as a primary mineral in olivine-rich basalts and andesites. In these rocks it can be present in quantities of a few weight percent. Diopside also forms during contact metamorphism of limestones and dolomites. Most of the crystalline diopside used to cut faceted gems and the granular diopside used as ornamental stone occurs in these…

Diopside is a rock-forming pyroxene mineral with a chemical composition of MgCaSi2O6. It occurs in igneous and metamorphic rocks at many locations around the world. Gem-quality crystals of diopside are faceted into attractive gemstones that are occasionally seen in commercial jewelry. Granular diopside can be easily cut and polished. When it has an attractive color, it is sometimes used as an ornamental stone. Perhaps the most…