Tourmaline Growth Diary

Source note

Edit the sample or paste another specimen description. Parse only after the note is ready.

Spent way too long staring at this Coronel Murta tourmaline spray before writing anything down, so let me just walk through what's going on. Five or six crystals off one feldspar base, and no two are colored the same way. Brown fading into rhubarb red on one, colorless running into teal on another, a few with bright fiery red caps right at the tip. That banding along a single crystal comes from the pocket fluid itself changing composition while the crystal is still growing. Tourmaline's structure is pretty forgiving about what cations it lets into those octahedral sites, so as the residual boron-rich melt gets enriched first in iron, then manganese, then lithium, the crystal just records whatever chemistry is on offer at that moment. Each color band is basically a timestamp. Slice a crystal like this and you're looking at a growth diary, not a paint job. The habit variety here gets me almost as much as the color. Some of these terminate flat, capped off on the basal pinacoid, others come to a sharp pyramidal point. Not a cosmetic accident - it usually tracks how much boron and coloring ions were reaching that particular face as growth slowed or sped up near the end. Different individuals in the same pocket can finish completely differently depending on where they sat relative to fluid flow, even growing side by side. And a spray like this, several terminations still intact, perched on cleavelandite blades over a feldspar host, is exactly why pocket material commands the money it does. A loose crystal is a nice specimen. A cluster where you can watch the whole growth sequence play out across multiple individuals at once, still attached to matrix, is a display piece. Stop-and-stare stuff, the kind where you start doing the math on how it ever came out of the ground in one piece. Link in 🧨

Waiting for the pinned parser.

Evidence wall

No growth diary yet.

WAITING

Sentence units0

Source groups0

Parse the note to place exact source sentences beside their supported growth reading.

The completed map will keep qualitative growth evidence separate from measurements it cannot verify.

Read the crystal's growth diary.

Source note

No growth diary yet.