3 spectrolite cabochon brooch from Finland (Ylämaa)

Spectrolite

Spectrolite of Finland - the most beautiful labradorite in the world.

Spectrolite quarried from the rugged bedrock of Ylämaa in the South East of Finland is a Finnish gemstone which meets the three basic requirements: beauty, hardness and rarity. Spectrolite is a labradorite feldspar, a member of the albiteanorthite series with approximately 55% anorthite. Its composition is Na (AlSi308), Ca(A12Si208), hardness 6-6,5, refractive indices 1.56-1.57, specific gravity 2.69-2.70 and double refraction 0.008.

Spectrolite was found in 1941during World War 2 when the finns built a defence line on the eastern border. Spectrolite crystals were found in stones raised as antitank obstacles. After the war, the quarrying of the precious stone started on a small scale, increasing in the 50s. In 1973 the first cutting and polishing workshop started to make spectrolite jawels in Ylämaa.

The fascination of spectrolite lies in its richness of colour and changeng tones, which are more remarkable the larger the stone is. The colours have all the shades of the spectrum and reflect the rich hues of Finish scenery - from golden browns to darkest blues. What causes the play of colours is not yet quite known, but interference of light waves in th in layers of material w light is reflected seems to play a role.

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