白云鄂博
Inner Mongolia, China
白云鄂博位于内蒙古包头以北,是地球上已知最大的稀土元素矿床,也是巨型的铁–铌–稀土矿床。对收藏者而言,它是碱性岩矿物的著名产地——霓石、钠闪石,以及一长串稀有的稀土与铌矿物——但矿区准入受限,标本稀少。
The world's largest rare-earth deposit
Bayan Obo is a giant iron–niobium–rare-earth-element (Fe–Nb–REE) deposit hosted in dolomitic carbonatite and alkaline rocks on the northern margin of the North China Craton. It holds a very large share of the world's known light-rare-earth reserves and has been mined for iron ore since the 1950s, with rare earths recovered as a co-product. The deposit was first reported in 1927.
Why it matters to collectors
The alkaline-carbonatite setting produces an unusually rich suite of minerals. Bayan Obo is the type locality for a number of rare REE, niobium, and barium species, and yields well-known collector minerals including aegirine, riebeckite, arfvedsonite, fluorite, fluorapatite, magnetite, hematite, bastnäsite, and monazite. Its mineralogical diversity makes it one of the most-studied localities in China.
Availability
Bayan Obo is a strategically important, security-controlled operation, so crystallized collector specimens rarely reach the open market. Pieces with documented Bayan Obo provenance are correspondingly prized, especially sharp aegirine and the rarer REE accessory minerals.
