LOT 5 pc 1.20 ct RED MIMETITE – CHINA

Mimetite

Mimetite is the ultimate “great pretender” of the mineral world. It is a lead arsenate that so closely resembles its cousin, Pyromorphite, that early mineralogists struggled to tell them apart without a chemical test. I’ve always found Mimetite to be one of the most cheerful minerals in the vault; its colors range from a bright, sunny lemon yellow to a deep, saturated “carrot” orange. It often forms in rounded, globular masses—which we call botryoidal—that look like clusters of golden grapes, or as sharp, resinous hexagonal prisms. Whether it is the classic yellow “campylite” variety or a sparkling druse of orange needles, Mimetite brings a vibrant, high-energy warmth to any collection of secondary lead minerals.

The Heritage & Discovery

Historical Significance: Mimetite represents a fascinating chapter in the evolution of mineral chemistry. It belongs to the apatite group and is part of a solid-solution series with Pyromorphite and Vanadinite. Historically, it was a significant indicator of oxidized lead and arsenic deposits. For collectors, it has always been a “must-have” because of its structural perfection and its ability to bridge the gap between common ores and exotic, colorful display pieces. It stands as a reminder that nature often repeats its most beautiful forms across different chemical families.

Discovery: The mineral was officially named in 1832 by François Sulpice Beudant. He chose the name from the Greek word mimetes, meaning “imitator,” specifically referencing its visual similarity to Pyromorphite. Before this, it was often confused with “green lead ore” or “arsenical lead.” Its formal classification allowed collectors to finally distinguish between the phosphate-dominant and arsenate-dominant members of the series.

Important Mines: While Mimetite is found in many lead districts, the Tsumeb Mine in Namibia is world-famous for producing some of the most spectacular, large, and varied Mimetite crystals ever found. Another legendary source is the Ojuela Mine in Mapimí, Mexico, which is renowned for its brilliant “mushy” botryoidal yellow specimens. I also have a high regard for the material from the Hat Yai area here in Thailand and various mines in China, which have recently produced world-class, lustrous orange hexagonal prisms. We source from these specific localities to ensure the most vibrant saturation and “wet-look” luster.

Mineralogical Profile

Description: Mimetite is a lead arsenate chloride that crystallizes in the hexagonal system. It sits at a 3.5 to 4 on the Mohs scale, making it a relatively soft mineral best suited for display or careful handling. It is characterized by its resinous to adamantine luster, which gives the crystals a sparkling, jewel-like quality.

The crystals can be prismatic, acicular, or even barrel-shaped (campylite). It is very dense due to its lead content, and its color is primarily driven by the presence of arsenic and trace impurities. When the arsenic is partially replaced by phosphorus, the mineral trends toward Pyromorphite, and when replaced by vanadium, it moves toward Vanadinite.

Chemical Formula: Pb₅(AsO₄)₃Cl