LOT 2.35 ct 8 pcs MOTTRAMITE – USA

Mottramite

Mottramite is a mineral that brings a rich, forest-green or earth orange intensity to any collection. It is a lead copper vanadate that often forms in velvety, botryoidal (grape-like) crusts or as drusy coatings of tiny, sparkling crystals. I have always found Mottramite to be a fascinating study in texture; when the crystals are very fine, the surface looks like green suede, but under a lens, it reveals a world of sharp, complex geometry. It represents the vibrant final stages of mineral alteration in the oxidation zones of base-metal deposits. Whether it is the deep olive green or the rare, almost black-green varieties, Mottramite carries an organic, earthy beauty that feels like moss frozen into stone.

The Heritage & Discovery

Historical Significance: Mottramite is a key member of the Descloizite group and is an important secondary ore of vanadium. Historically, it has been studied for its relationship with its zinc-dominant cousin, Descloizite, as the two often form a solid-solution series. It represents the geochemical “recycling” of lead and copper in the presence of vanadium-rich fluids. For collectors, it is a classic “secondary” mineral, prized for its ability to coat other minerals in a vibrant green crystalline carpet, often creating spectacular multi-mineral specimens.

Discovery: The mineral was first described in 1876 and was named after its type locality in Mottram St. Andrew, Cheshire, England. It was discovered in the local sandstone-hosted copper deposits, which provided early mineralogists with unique examples of vanadate chemistry in a sedimentary environment. Since its discovery, it has been identified in oxidized zones worldwide, becoming a staple of systematic mineralogy.

Important Mines: While the English type locality is historic, the most famous and aesthetically pleasing specimens come from the Tsumeb Mine in Namibia. Tsumeb produced legendary Mottramite specimens, often associated with bright white Cerussite or orange Wulfenite, creating a stunning color contrast. Other world-class material has emerged from the Berg Aukas mine in Namibia and the Ojuela Mine in Mapimí, Mexico. I always look for these Mexican and Namibian pieces, as they offer the most lustrous and well-defined “velvet” surfaces.

Mineralogical Profile

Description: Mottramite is a lead copper vanadate hydroxide that crystallizes in the orthorhombic system. It sits at a 3 to 3.5 on the Mohs scale, making it a soft mineral that is strictly for display or specialized collector jewelry. It is characterized by its vitreous to greasy luster and its range of green hues, from yellowish-olive to nearly black. It often forms as mammillary crusts or small, prismatic crystals. Because it contains both lead and vanadium, it is quite dense for its size, a characteristic “heaviness” that collectors often use to help identify the species in the field.

Chemical Formula: PbCu(VO₄)(OH)