Lepidolite: meaning, properties and lore

The mineral

It is one of the few minerals with appreciable amounts of rubidium, and its formula is given as K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2. Lepidolite belongs to the mica family and is a silicate of the phyllosilicate class, with perfect cleavage in one direction and a pearly to vitreous luster.¹²⁴⁷⁵³

Lepidolite has a Mohs hardness of 2.5 to 3.5 and a specific gravity of 2.8 to 3.0. It crystallizes in the monoclinic system, and it forms a solid solution series from polylithionite to trilithionite, known as the lepidolite series. The mineral can be impregnated with quartz, which gives durability, though lepidolite alone lacks the hardness and tenacity for gem use.⁵⁴

Manganese is the cause of the pink, red and purple colour in lepidolite, and lithium rarely serves as a chromophore in minerals. The Burma specimen described in the Mogok study was lilac, uniform except where bleached white, and its thicker patches showed pleochroism from faint pink to deep lilac.⁵⁸⁹

Lepidolite occurs almost exclusively in granite pegmatites, and it forms in late-stage magmatic rocks such as pegmatites, greisens and hydrothermal quartz veins. It can only form where high concentrations of lithium are available, which is why it is rare. Its forms include disseminated particles, fine-grain aggregates, flat sheet books and curved sheet aggregates.¹⁴⁵

Notable lepidolite occurrences include Minas Gerais in Brazil, Manitoba in Canada, Honshu in Japan, Madagascar, the Ural Mountains in Russia, Skuleboda in Sweden, California, Maine and New Mexico in the United States, and Coolgardie in Western Australia. In California, lepidolite is found at Pala in San Diego County, where a pegmatite dike lies within a high norite hill in the Peninsula Range. It is associated there with rubellite tourmaline, quartz, feldspar, muscovite, garnet and hematite.⁵⁶

Lepidolite is economically important as a major source of lithium and is used as a lithium ore, processed by hydrochloric acid to make lithium chloride. Lepidolite frequently occurs alongside tourmaline but is usually seen in lower-quality stones or collector specimens. Lithium mica production from lepidolite continued at the Stewart Mine near Pala until about 1928.¹²¹⁰

History and lore

Lepidolite is also known as lithia mica, a name recorded in the Britannica encyclopedia as its alternative name. Lepidolite was first noted as a California mineral in early state mineral lists by Professor Blake and Mr. Hanks, who mentioned it with rubellite in the San Bernardino range. The name lithia mica reflects its lithium content, the element that made the mineral valuable.¹¹¹

Henry G. Hanks, in 1884, mentioned a specimen of lepidolite with rubellite in the State Mining Bureau from San Diego County and remarked that lithium might someday be extracted from it. Charles Russell Orcutt announced the Pala lepidolite locality in 1892, which George Kunz recorded in his 1893 report. Lepidolite was mined at Pala in 1892, with about eighteen tons mined that year.¹¹

Harold W. Fairbanks, of Berkeley, California, published notes on the occurrence of rubellite and lepidolite in Southern California in Science in 1893. Those notes described the Pala dike as a well-defined vein filled with minute needle-like rubellite crystals, with quartz crystals scattered through it. The Mesa Grande locality was found in 1898 by prospectors searching for lepidolite on Mesa Grande Mountain at about 5000 feet altitude.⁶⁷

At the Pala locality the lepidolite is pale lilac in colour, with pink tourmaline crystals embedded in it. Lepidolite was mined at Pala by the ton, partly for specimens and partly for extracting lithia compounds. In 1901 California produced lepidolite to the value of $27,500. Lepidolite at Mesa Grande was found in larger and more brilliant scales than at Pala.⁷¹¹

Lepidolite-bearing pegmatite at the Stewart Mine contained clusters and sprays of small red rubellite tourmaline crystals. Muscovite mica crystals with rims of lepidolite mica were described from the Tourmaline Queen mine in the Pala district. Gem-quality lepidolite crystals have been described in a 1984 Gems & Gemology article by John I. Koivula and C. W. Fryer.¹⁰³

Birthstone, zodiac and chakra links

Lepidolite appears as an October birthstone, and practitioners pair it with the modern sign Libra, a connection they treat as recent rather than ancient.

Lepidolite is often associated with the third eye chakra and the crown chakra, according to crystal practitioners, and this chakra link is a modern one.

What crystal practitioners say

Crystal practitioners associate lepidolite with the mind, describing it as a stone of calmness, trust and acceptance. It is called the peace stone, and it is said to promote calm and reduce stress. Practitioners also say it is said to promote communication between the conscious and subconscious mind.

Crystal practitioners ascribe a protective role to lepidolite, and it is said to protect against EMF radiation by creating a barrier around the body that deflects negative energy. Users who hold this view describe the stone as a shield rather than a treatment. The protective claim is one that practitioners make and no test in the claims supports it.

Crystal practitioners say lepidolite should be cleansed with moonlight baths or by placing it on a bed of sea salt overnight. Practitioners describe these cleansing methods as their own practice for the stone. Lepidolite is cut into slabs for ornamental objects such as ashtrays, paperweights and bookends, which are its everyday uses in the claims.¹²⁴

What testing has found

In his analysis of 150 complementary and alternative treatments, Edzard Ernst found no rigorous trials testing the therapeutic value of crystal healing. He concluded that no scientific proof exists for any positive effect beyond a placebo effect. He attributed pleasant feelings reported from crystal healing to the strong placebo effect and to cognitive bias, where believers notice only what supports their belief.¹³

British psychologist Christopher French ran a 2001 study in which 80 volunteers, after holding crystals and meditating, had to tell real crystals from fake ones. Six participants felt nothing, while the rest described sensations such as tingling or an improved sense of wellbeing. Those holding fake crystals reported impressions similar to those holding real ones, pointing to a possible placebo effect.¹³

Researchers concluded that crystals did not help people and that suggestion was the operative factor. Some scientists argue that crystals probably do not directly affect physical or psychological complaints, though they may offer indirect benefits attributable to placebo.¹⁴

Ted Kaptchuk, a Harvard Medical School professor, said placebo effects from unconventional medicine may be dramatic and especially compelling to patients. Rigorous scientific research on crystal therapy is lacking, and the scientific community remains skeptical. Permutt, a crystal practitioner, says there is no proven link between crystals and the body and that how crystals affect the body is still unclear.¹⁴