Jadeite is a silicate mineral recognized as the rarer and more valuable of the two minerals commonly called “jade.” Prized for millennia for its striking beauty and exceptional durability, this stone holds significant cultural importance. In East Asia, it became a powerful symbol of status and purity, introduced to China toward the end of the 18th century where it was known as fei cui. Simultaneously, in Mesoamerica, the Olmec and Maya peoples valued bright green jadeite more highly than gold, using it extensively in religious and ceremonial artifacts.
Defining the Mineral: Composition and Structure
Jadeite is scientifically classified as a pyroxene mineral, a group of chain silicates found in igneous and metamorphic rocks. Its composition is sodium aluminum silicate. The crystal structure is monoclinic, characterized by long chains of silica tetrahedra bonded together by aluminum and sodium ions.
The unique, compact internal structure of interlocking, granular crystals gives jadeite its exceptional toughness and resistance to breaking or chipping. The mineral exhibits a Mohs hardness ranging from 6.5 to 7.0, indicating its resistance to scratching. It is also dense, possessing a specific gravity that typically falls between 3.24 and 3.43.
While most famous for its vivid green, jadeite occurs in a wide spectrum of colors, including lavender, white, yellow, orange, and black. Trace elements determine the color, such as chromium causing the sought-after emerald-green hue known as “Imperial Jade.” Lavender jadeite gains its color from traces of manganese, while iron can cause yellow or reddish tones.
Jadeite vs. Nephrite: Clarifying the Term “Jade”
The term “jade” is a cultural designation that encompasses two distinct mineral species: jadeite and nephrite. Although they can appear visually similar, they are chemically and structurally separate, belonging to different mineral groups.
Nephrite, by contrast, is a calcium magnesium iron silicate and belongs to the amphibole group of minerals. Its microstructure is composed of densely interlocked fibrous crystals, giving it a slightly lower hardness of 6.0 to 6.5 on the Mohs scale, but making it extremely tough.
Jadeite is notably harder and possesses a higher density than nephrite, accounting for its glass-like luster compared to nephrite’s more waxy sheen. The difference in rarity is a defining factor, as gem-quality jadeite deposits are much more isolated and scarce, leading to a much higher market valuation. Furthermore, jadeite displays a wider range of vibrant colors, while nephrite tends toward muted tones of creamy white, olive green, and dark brown.
Valuation and Geographical Sources
Several factors contribute to the high value of jadeite, with color saturation, transparency, and texture being the most significant qualities. The most prized color, “Imperial Jade,” is a vibrant, uniform emerald green with a high degree of translucency. Transparency is highly valued, as the finest pieces possess a near-glassy appearance that allows light to penetrate deeply.
Jadeite is classified using a commercial grading system that denotes the presence or absence of treatments. Type A jadeite is the most valuable, referring to natural stone that has only been cut and polished. Type B jadeite has been chemically treated, typically bleached with acid to remove impurities, and then impregnated with polymer resin to stabilize the structure. Type C jadeite has undergone the bleaching and polymer treatment of Type B, with the addition of artificial dyeing to enhance or change the color.
The geological formation of jadeite requires high pressure and relatively low temperature, leading to rare and isolated deposits. The premier source for the world’s highest quality jadeite is the Kachin State in Myanmar, formerly known as Burma, which is the origin of nearly all “Imperial Jade.” Secondary sources exist in the Motagua Valley of Guatemala, historically important to the Maya, and deposits are also found in parts of Russia and Japan.