Greenstones & copper minerals

What holds the family together

These five stones are chemically unrelated. Jade is either jadeite, a pyroxene, or nephrite, an amphibole. Turquoise and apatite are phosphates. Chrysocolla is a hydrated copper silicate. Larimar is a blue variety of pectolite, a calcium sodium silicate.

What connects them is a shared range of blue-green colour, mostly from copper, and a shared history of being the highest-valued material in the cultures that had access to them.

Two of them are notable for toughness rather than hardness. Nephrite jade in particular is a felted mass of interlocking fibres, which makes it extraordinarily difficult to break; it is tougher than steel by some measures, and that is why it was worked into axes and adzes long before it was worked into ornaments. Its hardness is only about 6, so it scratches, but it does not shatter.

Turquoise, by contrast, is porous, which is the single most important fact about owning it.

How it forms

Jadeite is rare and forms only at high pressure and low temperature, in subduction zones. The two significant ancient sources are Myanmar, which supplied China from the eighteenth century, and the Motagua valley in Guatemala, which supplied the Olmec and the Maya. Nephrite is more widespread and was the jade of ancient China itself, from Khotan in the Tarim basin.

Turquoise forms in arid regions where copper-bearing groundwater percolates through aluminous rock. Egypt worked Sinai from before 3000 BCE, Persia mined Nishapur for millennia, and the American Southwest, notably Cerrillos in New Mexico, has been worked for around two thousand years.

Chrysocolla forms in the oxidised zone of copper deposits alongside malachite and azurite.

Larimar is the family's outlier: a single deposit in the Dominican Republic, brought to market only in 1974, with no traditional lore of any kind.

The stones of this family

• Turquoise (CuAl₆(PO₄)₄(OH)₈, Mohs 5.5). Mined in Sinai before 3000 BCE and in the American Southwest for two thousand years. Porous, easily discoloured by oils, and among the most faked stones on the market.
• Apatite (Ca₅(PO₄)₃(F,Cl,OH), Mohs 5). The mineral your own teeth and bones are made of, which is a better fact than most of its modern lore. Soft, and easily confused with better stones.
• Jade (jadeite or nephrite, Mohs 6.5). Two different minerals under one name, and the most culturally loaded stone on earth. Confucius read the five virtues in it; Mesoamerica valued it above gold.
• Chrysocolla (hydrated copper silicate, Mohs 3). Blue-green copper silicate, often stabilised in quartz to be workable. Named by Theophrastus for its use as a gold solder, which is what the word means.
• Larimar (blue pectolite, Mohs 6). Found in one small area of the Dominican Republic and nowhere else, brought to market in 1974. Its lore is fifty years old and openly so.

Trade names and lookalikes

This family has the worst naming problems in the catalogue.

Jade first. Both jadeite and nephrite are genuine jade. Serpentine, aventurine, dyed quartzite, prehnite and glass are all sold under jade-adjacent names, of which new jade for serpentine is the most common. Jadeite is graded A, B and C: A is untreated, B has been bleached and resin-impregnated, and C has been dyed. B and C material is worth a fraction of A and can degrade over years.

Turquoise is worse. The great majority of what is sold is dyed howlite or magnesite, reconstituted powder in resin, or plastic. Even genuine turquoise is usually stabilised, meaning resin-impregnated to make soft material workable, which is honest and normal when declared.

Chrysocolla is frequently sold in a silicified form, chrysocolla in chalcedony, which is genuine and much more durable than pure chrysocolla at hardness 3.

Larimar is faked with dyed howlite and with resin.

Care that follows from the structure

Softness and porosity define the care here.

Turquoise absorbs everything: skin oils, hand cream, perfume, sunscreen, detergent. All of them shift its colour towards green and can stain it permanently. Older traditions read that change as the stone recording the wearer's life, which is a graceful description of a chemical reaction. If you would rather keep it blue, put it on after cosmetics and take it off before washing up.

Jade takes daily wear well because of its toughness, and Chinese practice actively favours handling it, since skin oils build a patina over years. It should still be kept out of high heat, which can damage treated material and dull the polish.

Chrysocolla and larimar are soft and should be treated as pendant stones.

None of the copper members should be used for direct-contact gem waters.