Jade is a material with a history spanning millennia, yet the term itself does not refer to a single stone. Instead, “jade” is a cultural name encompassing two distinct mineral species: nephrite and jadeite. The geographical distribution of these two materials is important for understanding why specific types of jade have been historically or commercially valued.
The Distinct Mineral Forms of Jade
Jadeite and nephrite are chemically and structurally distinct, despite their similar appearance and shared name. Jadeite is a sodium and aluminum-rich pyroxene, forming under conditions of high pressure and relatively low temperature in metamorphic rock environments. This mineral is generally harder, scoring between 6.5 and 7 on the Mohs scale, and possesses a vitreous, or glass-like, luster.
Nephrite, by contrast, is a calcium and magnesium-rich amphibole, which forms under less extreme metamorphic conditions than jadeite. Though slightly softer, with a Mohs hardness of 6 to 6.5, nephrite is significantly tougher due to its densely interlocked, fibrous crystal structure. This fibrous structure made it the preferred material for tools and weapons in ancient cultures.
Jadeite is known for a wider range of vibrant colors, including lavender, pink, and the highly prized, translucent “Imperial Green,” which gets its color from trace amounts of chromium. Nephrite’s color palette is typically more muted, featuring creamy whites, olive greens, and black, notably including the revered white “mutton fat jade” of China.
Primary Global Sources of Jadeite
The global supply of gem-quality jadeite is geographically concentrated, with a single country providing the vast majority of the world’s finest material. Myanmar, formerly known as Burma, is the primary source of high-quality jadeite, supplying upwards of 70% of the world’s supply. The most significant deposits are found in the northern region of Kachinland, specifically within the remote “Jade Tract” near the town of Hpakan.
This region is the only known source for the world’s most valuable material, “Imperial Green” jadeite. The jadeite occurs as pod-like bodies within massive serpentinite deposits, which are mined both in situ and from alluvial deposits. The jade from Myanmar is predominantly exported to other Asian countries, where it is used for jewelry and carvings.
While Myanmar dominates the high-end market, other countries have notable jadeite deposits. Guatemala is recognized as a secondary but historically significant source, where bright green jadeite, known as “quetzal” jade, was treasured by ancient Mesoamerican cultures. Minor deposits have also been documented in places like Russia, Kazakhstan, and California.
Widespread Sources of Nephrite Jade
In contrast to the restricted sources of jadeite, nephrite jade is found in numerous locations across the globe, reflecting its more common geological formation. Canada, specifically British Columbia, is the largest modern commercial source of lapidary nephrite. These deposits extend along a belt of ultramafic rock that runs for over a thousand miles through the province.
Historically, China’s Xinjiang region has been a significant source, particularly the Kunlun Mountains near the ancient city of Khotan. The rivers flowing from these mountains, such as the Yurungkash (White Jade) and Karakash (Black Jade) rivers, were famous for yielding high-quality nephrite pebbles and boulders. This material has been treasured in Chinese culture for thousands of years.
Other major suppliers include Russia, with deposits in Siberia near Lake Baikal known for their distinct, vibrant green nephrite. New Zealand is also a renowned source, where the nephrite is known by the Māori name pounamu or “greenstone.” In the United States, commercially viable nephrite deposits exist in states such as Wyoming and Alaska.
Sourcing and Discovery Methods
Jade is typically sourced using two main discovery methods: extracting the stone directly from the bedrock or collecting it from secondary deposits. Hard rock mining, or in situ extraction, involves removing the jade from its primary source, where it formed within the surrounding host rock. This method is necessary for accessing the massive, unweathered jade bodies deep within the earth.
The second method involves collecting jade from alluvial and eluvial deposits, which are often found in riverbeds or in gravels along the banks. In these secondary locations, the jade has been naturally transported and worn smooth by water, sometimes exposing the quality of the stone. This process often yields smaller pieces, ranging from pebbles to large boulders.
Miners frequently rely on the presence of a weathered outer layer, sometimes called the “rind,” to indicate the presence of jade beneath the surface. This rind is a crust of altered material that forms on the exterior of the stone, often obscuring the true color and quality of the jade. Recognizing the subtle signs of jade in these environments is a specialized skill.