Crystal
Green and mottled like a snake's back — a whole mineral group, and one to know something about before you cut it.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Serpentine is not one mineral but a group — antigorite, lizardite and chrysotile chief among them — all magnesium silicates formed when water works on the olivine and pyroxene of mantle rock. The name is from the mottled green skin the massive varieties show. Lizardite takes its name from the Lizard Peninsula in Cornwall, where the serpentinite has been quarried and turned since the nineteenth century and where the ornamental trade still runs.
One member of the group needs stating plainly. Chrysotile is the fibrous variety, and chrysotile is white asbestos. Most ornamental serpentine sold as a carving or a tumbled stone is antigorite or lizardite rather than chrysotile and is not fibrous, but anyone cutting, grinding or sanding raw serpentine should know what they have and work wet with proper extraction. This is a workshop caution about dust, not a claim about anything else.
Practice associates it with the earth's own processes and with slow renewal, and — following the name — with shedding, in the way a snake sheds. That reading is old enough to be found across several European traditions and is one of the more transparently name-driven correspondences in the whole compendium, which is not a reason to dismiss it so much as a reason to see clearly what it is.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Common in contemporary practice
Kept through a period of leaving something behind, on the snake-shedding reading. It is a correspondence built on a name given for a pattern, which practitioners generally know and generally do not mind — the image does the work whether or not the etymology deserves the credit.
Carried forward
Common in contemporary practice
Widely sold as new jade, which it is not. Serpentine is softer, warmer to the touch and considerably cheaper than either nephrite or jadeite, and a seller who uses the term without qualifying it is worth a second question.
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.