Crystal
Blue-green copper silicate, soft as chalk on its own — and named for gluing gold.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Chrysocolla is a hydrated copper silicate that forms as a crust in the weathered upper zones of copper deposits, usually alongside malachite and azurite. On its own it is extremely soft — as low as 2 on the Mohs scale, which is fingernail territory — and the pieces sold as jewellery are almost always chrysocolla that has been infiltrated by silica, or thin seams of it inside chalcedony. That last combination is sometimes called gem silica, and it is one of the more expensive chalcedonies.
The name is Greek: chrysos, gold, and kolla, glue. Theophrastus and Pliny both use it for a substance used as a solder or flux in goldworking, and while the ancient chrysocolla was probably not quite this mineral, the etymology has stuck to it. Copper workings at Timna in the southern Negev and in the Atacama have produced it for millennia as a by-product of ore extraction.
Practice puts it at the throat, and specifically with speech that has been held back too long — a quieter, more inward version of what amazonite is asked to do. Like malachite it is a copper mineral, and the same practical caution applies: cut it wet, do not grind it dry, and keep it out of anything anyone intends to drink.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Common in contemporary practice
Reached for when something has gone unsaid for a long time rather than when something difficult has to be said now. The distinction from amazonite is one practitioners draw carefully, and it is about timing rather than about courage.
Carried forward
Pliny the Elder, Natural History, Book 33 (c. 77 CE)
Pliny discusses chrysocolla among the materials of the goldsmith rather than among the gems, describing its preparation as a solder. The stone we call by that name today inherited the word from a workshop, not from a jeweller's tray — a reminder that most old stone names were job descriptions first.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.