Lepidolite

Lepidolite

Lepidolite is a lilac-gray or rose-colored member of the mica group of minerals with the formula K(Li,Al)₃(Al,Si,Rb)₄O₁₀(F,OH)₂. It is the most abundant lithium-bearing mineral and is a secondary source of this metal. Lepidolite is a phyllosilicate mineral and is part of the polylithionite-trilithionite series.

Properties

Lepidolite is known for its high lithium content, which can be up to 3.5% by weight. It is a significant source of lithium, which is used in the production of lithium-ion batteries, ceramics, and glass. The mineral is also rich in rubidium and cesium, which are used in various industrial applications.

Physical Properties

• Color: Lilac, rose, gray, yellowish, colorless
• Crystal habit: Tabular to prismatic crystals, often in aggregates
• Cleavage: Perfect on {001}
• Fracture: Uneven
• Mohs scale hardness: 2.5 - 3
• Luster: Vitreous to pearly
• Streak: White
• Specific gravity: 2.8 - 2.9

Chemical Properties

Lepidolite is a complex silicate mineral that contains lithium, aluminum, silicon, and oxygen, with fluorine and hydroxyl groups. It often contains trace amounts of rubidium, cesium, and other elements.

Occurrence

Lepidolite is typically found in pegmatites, which are coarse-grained igneous rocks. It is often associated with other lithium-bearing minerals such as spodumene, petalite, and amblygonite. Notable deposits of lepidolite are found in Brazil, the United States (California, Maine), and Africa.

Uses

Lepidolite is primarily used as a source of lithium. The extraction of lithium from lepidolite involves a series of chemical processes, including roasting and leaching. The mineral is also used as a heat insulator in industrial applications and as a decorative stone in jewelry and ornamentation.

Health and Safety

While lepidolite itself is not considered hazardous, the dust generated during mining and processing can pose respiratory hazards. Proper safety measures, including dust control and personal protective equipment, are essential to minimize exposure.

Also see

• Lithium
• Mica
• Pegmatite
• Spodumene
• Petalite