Lepidolite

Lepidolite is a lilac, pink or purple mica that contains lithium. It usually occurs in granite pegmatites, together with spodumene and tourmaline. It is the most abundant lithium-bearing mineral and a secondary source of lithium, and also an important source of rubidium. Today it is not a separate species recognised by the International Mineralogical Association but a shared name for the lithium micas between polylithionite and trilithionite.

Lithium ore: As the most abundant lithium-bearing mineral, it is a secondary source of lithium. In 2022 China was reported to have 22 lepidolite mines with valid mining rights, and lithium is also mined in countries such as Zimbabwe. Lithium is one of the key materials of electric-vehicle batteries. Source of rubidium: Lepidolite is one of the main sources of rubidium, used in atomic clocks, lasers and fireworks. Ornamental stone: Lilac-pink scaly masses are cut and polished into beads and ornaments.

It has a hardness of 2.5–3 on the Mohs scale. A fingernail cannot scratch it, but a steel knife can. Its specific gravity is 2.8–2.9 g/cm³.

Its best-known localities: Rožná, near Bystřice nad Pernštejnem, Czechia; Pala district, San Diego County, California, USA; Bikita, Masvingo, Zimbabwe; Tanco mine, Bernic Lake, Manitoba, Canada; Yichun area, Jiangxi, China.

Thin lilac, pink or purple flakes with a pearly shimmer, or scaly masses; it is very soft (hardness 2.5–3) and splits into leaves even with a fingertip. Its flakes are flexible and elastic: they spring back when bent and released. In pegmatites it occurs with spodumene, tourmaline (elbaite), amblygonite, quartz and other micas.

On the “street to diamond” value ladder it sits on step 4 of nine: Fine dimension stone and ore. As a lithium ore, the value of lepidolite depends on its lithium content, the size of the deposit, the cost of separating the lithium from the ore and the demand of the battery industry; most of the world's lithium production comes from brines and from other minerals such as spodumene, and lepidolite is a secondary source. As an ornamental stone, a vivid pink-purple colour, evenness of colour and soundness of the mass matter; it is very soft and scratches easily. Collectors look for large plates and specimens that occur with fine companions such as tourmaline.

Today crystal-therapy sources present lepidolite as a “peace stone” and claim that, because of the lithium in it, it soothes anxiety and stress and calms the mind. The same sources say that the stone relaxes the nervous system, strengthens the immune system and may ease depression and anxiety. Lepidolite does contain lithium, but the lithium is locked into the crystal structure and holding or carrying the stone does not pass lithium into the body. The lithium medicines that regulate mood are prescription drugs whose blood level is monitored in a laboratory; a stone cannot take their place. For anxiety, depression or mood problems, see a doctor, and do not stop medication for the sake of a stone. Lepidolite powder should not be swallowed and no stone water should be made from it: besides lithium, the stone contains fluorine and rubidium. This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment.

Besides lithium, lepidolite also contains fluorine and rubidium. The powder should not be swallowed and no stone water or elixir should be made from it; the fine mica dust released in cutting and grinding should not be inhaled either.