Labradorite Palm Stone Grade AAA.

Labradorite is a calcium-sodium plagioclase feldspar with the composition (Ca,Na)(Al,Si)₄O₈. Triclinic. Mohs 6–6.5. The body of the stone is a dark grey to grey-blue, sometimes almost black, with the polished surface holding a smooth vitreous lustre.

The distinguishing property is labradorescence - the iridescent play of colour (blue, green, gold, occasionally orange) that appears when the stone is tilted in the light. The colours are not a coating, not a pigment; they come from the internal microstructure of the stone itself. As the rock cooled slowly over geological time, the feldspar separated into alternating thin layers of two slightly different compositions. These layers are nanometre-thin, and when light strikes them it undergoes thin-film interference: the same physical mechanism that gives colour to a soap bubble or an oil film, translated into stone.

The stone was first identified in 1770 on the Isle of Paul off the coast of Labrador in northeastern Canada, and the mineral takes its name from the region. Commercial palm-stone material comes primarily from Madagascar; the highest-grade material in the world is quarried at Ylämaa in southeastern Finland and sold in the trade under the name spectrolite. The mineral appears in the Nain Plutonic Suite of Labrador itself in the largest deposits, though little of that stone reaches the polished-goods market.

Asked often

Why does it flash different colours?
Thin-film interference from microscopic layers inside the stone - the same physics that produces the colours on a soap bubble or an oil film. The stone contains alternating nanometre-thin layers of two slightly different feldspar compositions that separated as the rock cooled. Light bouncing between these layers produces the iridescent colours you see.
What does "Grade AAA" mean?
A trade grade denoting strong, wide-spectrum labradorescence across most of the stone's surface, with good body colour and minimal fractures. Trade grading is not standardised across the industry - one supplier's AAA may differ from another's - but within a single source, higher grades carry stronger colour play.
Where is it from?
The mineral was first identified in Labrador, Canada, and takes its name from the region. Commercial palm-stone material typically comes from Madagascar (the largest current source for the polished trade); the highest-grade material in the world is quarried in Finland and sold as spectrolite.
Why does the colour only show at certain angles?
Because thin-film interference is angle-dependent - the colour you see depends on the angle of the light source relative to the stone's internal layers and to your eye. Tilt the stone slowly under a lamp or in a shaft of daylight and the colours shift across the polished face. The effect is strongest in raking light (a low angle of incidence) and weakest with light coming from directly overhead.
How do I care for it?
Wipe with a soft cloth. At Mohs 6–6.5 it is moderately hard-wearing - hard enough to keep in a pocket, soft enough to scratch against harder stones or metal. Keep away from prolonged direct sunlight, which over years can slightly dull the body colour.

1. Held in the palm, the thumb resting in the face of the stone; tilt slowly in changing light to bring out the labradorescence.
2. Set on a windowsill or desk where daylight or lamplight strikes it at a low angle - the iridescence is most visible in raking light.
3. Carried in a pocket or a bag; hard enough for daily carry, soft enough to keep separate from keys and coins.
4. Wipe with a soft cloth. Away from prolonged direct sunlight.

Many traditions rinse or air their stones from time to time; that is a matter of preference, and the rest is yours.

A polished stone to keep and to hold. The colour comes and goes as the light and the angle change - part of the stone rather than a fault.

• Stone: Labradorite · calcium-sodium plagioclase feldspar
• Composition: (Ca,Na)(Al,Si)₄O₈
• Crystal system: Triclinic
• Hardness: Mohs 6–6.5
• Character: Dark grey-blue body · iridescent labradorescence (blue, green, gold flashes)
• Property: Labradorescence - thin-film interference from nanometre-scale lamellar structures
• Form: Palm stone · shaped and polished
• Approximate weight: 60–80 g per stone
• Grade: AAA · strong wide-spectrum labradorescence · minimal fractures
• Origin: Madagascar (commercial palm-stone source) · named after Labrador, Canada, where the mineral was first identified in 1770
• Care: Wipe with a soft cloth · avoid prolonged direct sunlight

The name comes from Labrador - the Canadian coast where the mineral was first identified in 1770 by Moravian missionaries settled in the region. The Inuit peoples of the Labrador coast held that the aurora borealis had once been trapped inside the rocks along the shore, and that a warrior struck the rocks with his spear to release the lights back to the sky; the stones that would not release their light are the labradorite that remains. A documented Inuit story of the region, named here as folklore. The mineralogical name entered the European scientific literature the same decade the folklore was recorded.

The highest-grade Finnish labradorite is sold in the trade as spectrolite - the same mineral species with unusually strong and wide-spectrum labradorescence, quarried at Ylämaa in southeastern Finland since the 1940s. Whatever the origin, the colour is a physical property of the stone itself: thin-film interference at the nanometre scale, brought into visibility by a tilt of the hand.