Sunstone Tumbled Stone

Sunstone is oligoclase, a plagioclase feldspar, holding thousands of microscopic hematite and goethite platelets that settled in parallel as the crystal grew. Light strikes the aligned plates and returns as a copper-gold flash - aventurescence, or schiller.

The flash moves with the angle of view, so the stone reads differently with every turn - quiet in shade, lit in sun. The body colour runs warm: oranges, honey-browns, soft reds.

A feldspar like the amazonite in this range: Mohs 6–6.5, slightly softer than the quartzes, with cleavage planes that ask the stones be spared hard knocks.

Asked often

What makes the glitter?
Thousands of flat hematite plates aligned inside the feldspar. Light strikes them together and returns as a single copper-gold flash - mineral, not coating.

Is it treated or man-made?
No. Sunstone is natural feldspar. Goldstone - the uniform glitter sold beside it in the trade - is man-made glass; this is the mineral the glass imitates.

Is this the Viking navigation stone?
The medieval Icelandic texts name a sólarsteinn used to find the sun through overcast sky - but scholars hold that stone was likely a clear calcite. This feldspar inherited the name, not the navigation.

How do I look after them?
Wipe with a soft cloth. A feldspar at Mohs 6–6.5, softer than quartz - guard them against hard knocks along the cleavage.

1. Carried in a pocket or a bag, or held in the hand.
2. Kept in a small dish, on a desk, or on a shelf - each stone is a little different.
3. Wipe with a soft cloth; a feldspar, softer than quartz, so spare them hard knocks.

Each stone is tumble-polished and unique, so a set varies a little stone to stone. Many keep a stone where they will see it each day, or carry one in a pocket; that is a matter of preference.

Pocket stones to keep and carry. Wipe with a soft cloth; a little softer than quartz at Mohs 6–6.5, so spare them hard knocks, which can chip a feldspar along its cleavage.

• Stone: Sunstone · oligoclase feldspar
• Hardness: Mohs 6–6.5
• Character: Warm body tones · copper-gold schiller
• Treatment: None · untreated
• Form: Tumbled stones · polished, each unique · sold in a set
• Origin: India
• Care: Wipe with a soft cloth · guard against hard knocks

The medieval Icelandic texts speak of a sólarsteinn - a sun-stone raised to the sky to find the sun through cloud. Modern scholarship holds that the navigators’ stone was most likely a clear calcite, not this feldspar; the feldspar inherited the name for the sun it appears to hold, and we tell the story honestly.

What is beyond dispute is the optical fact: aligned plates of iron oxide, set down as the crystal grew, returning the light together. Across the cultures that have worked it, the stone was read as a carrier of the sun - named here as what people believed.