05-27. Iolite – cordierite #7

Last day of the iolite. I’ll be missing its unique and inviting symmetry. I could work endlessly from the patterns of its cell structure. Maybe some future project…

From a resource by Malcherek, Domeneghetti, Tazzoli, Ottolini, McCammon and Carpente. A cordierite crystal from Zimbabwe.




05-26. Iolite – cordierite #6

Tessellation of an iolite unit cell polyhedra pattern. Center: iolite atoms in a cube.

From a resource by Malcherek, Domeneghetti, Tazzoli, Ottolini, McCammon and Carpenter. Great Bear Lake, Canada.



05-25. Iolite – cordierite #5

The is something so unique about the iolite structure – I could use it as an endless source of inspiration if I was a sculptor!

From a resource by Sokol, Seryotkin and Bul’bak. Cordierite from the Murzinka pegmatite field, Middle Ural Mountains, Russia.


05-23. Iolite – cordierite #3

Iolite unit cell, atomic arrangement & connection. It looks like an astronomer’s sky or planetary map. The very small and the very large are not that different. Background: tessellation of the same iolite unit polyhedral structure.

From a resource by Armbruster, single-crystal study from Ruby Island, New Zealand.


05-21. Iolite – cordierite #1.

Iolite – or cordierite as the mineral is also called, is week #21 theme of this 52-week tour of the geometry of nature. The iolite crystal has an amazingly harmonious and well organized – antic tessellation – look and structure.

The name “iolite” comes from the Greek word for violet. The crystal comes in blue, bluish violet; greenish, gray to very pale blue in thin section. It is also called “water-sapphire” or “Vikings’ Compass” because Leif Eriksson and other Viking explorers used it to determine the direction of the sun on overcast days. It may qualify as the world’s first polarizing filter.

Its structure belongs to the dipyramidal, orthorhombic family.

The largest iolite deposits today can be found in Madagascar, Myanmar, Sri Lanka, India, and Brazil.