Pyromorphite

Pyromorphite is a mineral made of lead, phosphate and chlorine (Pb₅(PO₄)₃Cl). It most often forms vivid green, yellow or orange crystals shaped like six-sided prisms, and it is very heavy. It appears in the upper parts of lead deposits where they meet air and water, as lead minerals such as galena break down. It matters little as an ore; its main audience is mineral collectors. Because it contains lead, it is toxic.

Lead ore: Its lead content is around 75–79% (government planning report); where it is abundant it is occasionally mined as an ore. Collecting: Its bundles and spheres of green, yellow and orange crystals are favourites of mineral collectors. Environmental science: Adding phosphate to lead-polluted mine waste and soils, so that the lead turns into pyromorphite-like minerals that barely dissolve in water, is a method being researched to reduce the transfer of lead to the environment and living things.

It has a hardness of 3.5–4 on the Mohs scale. A fingernail cannot scratch it, but a steel knife can. Its specific gravity is 6.5–7.14 g/cm³.

Its best-known localities: Bad Ems area (Friedrichssegen mine), Rhineland-Palatinate, Germany; Příbram, Central Bohemia, Czechia; Leadhills, Lanarkshire, Scotland; Phoenixville, Pennsylvania, USA; Santa Eufemia, Córdoba, Spain.

Known localities in Türkiye: Keban, Elazığ, Türkiye.

The colour is usually vivid green, yellow, orange or brown. Crystals are short or long prisms with a six-sided cross-section, sometimes slender needle-like bundles, sometimes spheres or kidney-shaped masses. It has a resinous lustre and is very heavy (specific gravity about 7): about two and a half times as heavy as a piece of quartz of the same size. Its hardness is 3.5–4: a steel knife scratches it, it is brittle, and its streak is white. Mimetite (arsenic-bearing) and vanadinite (vanadium-bearing) look very much like pyromorphite: all three share the same crystal structure, and pyromorphite and mimetite can grade into each other. Colour is not a reliable way to tell them apart; a laboratory analysis is needed for certain identification.

On the “street to diamond” value ladder it sits on step 4 of nine: Fine dimension stone and ore. As an ore, pyromorphite is worked only where it is abundant, according to its lead content (about three quarters of its weight) and the size of the deposit; in most deposits galena is the main source of lead. Collectors look for vivid, even green, yellow or orange colour, sharp, lustrous and undamaged crystals, a neat arrangement on the host rock, size, and origin from well-known places such as Daoping in China or Les Farges in France. Because it is soft and brittle, and because it contains lead, it is not suited to jewellery.

Crystal-therapy websites claim that pyromorphite helps with headaches, high blood pressure, gum disease and eye strain. The same sites say yellow and green pyromorphite balances the “solar plexus” and “heart chakras”, gives determination and courage, and that the green kind brings abundance. No study supports these claims. Pyromorphite is a lead mineral; lead is toxic and, according to the World Health Organization, there is no level of lead exposure that is known to be without harmful effects. It should therefore never be rubbed on the body, soaked in drinking water (“gem water”), put in the mouth, ground, or have its dust inhaled. Someone with high blood pressure or gum disease should not leave treatment to a stone but see a doctor. This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment.

Pyromorphite contains lead (about three quarters of its weight), a toxic metal that builds up in the body and can permanently damage the brain and nervous system, especially in children. According to the World Health Organization, there is no level of lead exposure that is known to be without harmful effects; exposure happens mainly by swallowing lead-contaminated dust, soil, water or food, and by breathing in particles released when lead-containing materials burn. Always wash your hands after touching pyromorphite and keep specimens out of children’s reach. Never put pyromorphite in your mouth, grind it, sand it or heat it, and do not breathe its dust. Never put it in drinking water.