Crystal
Deep blue with white running through it — the thinking stone, sober and unglamorous.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Named for its sodium content, which is about as romantic as mineralogy gets. Sodalite was described in 1811 from a Greenland occurrence, and for a century it stayed a specimen curiosity; the material most people handle today comes from a large Ontario deposit publicised after Princess Patricia admired it in 1901, which is why the Canadian trade name is princess blue. It is routinely mistaken for lapis lazuli and is the cheaper stone by a wide margin — the tell is that sodalite carries white calcite veining and almost never the brassy pyrite flecks lapis is known for.
Contemporary practice files it under the head rather than the heart: study, argument, holding a complicated thing in mind long enough to see its shape. It is one of the stones most often recommended to people who describe themselves as overthinking, which is a slightly odd fit — the stated logic is that it sorts thought rather than quieting it.
There is no classical lore here at all, because Europe did not know the mineral until the nineteenth century. Everything attributed to sodalite was written within living memory, and it is worth knowing that when a book presents its correspondences as ancient.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Common in contemporary practice
Kept on a desk during study or drafting. The claim made for it is organisational rather than inspirational: not that ideas arrive, but that the ones already present stop tangling. Nobody has demonstrated anything of the kind, and the people who use it this way are generally the first to say so.
Carried forward
Common in contemporary practice
Often paired with lapis lazuli, which practitioners describe as the same colour doing a warmer job. Where lapis is treated as regal, sodalite is treated as workmanlike — a distinction that owes at least something to price.
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.