Spectrolite is an uncommon variety of

labradorite Labradorite (( Ca, Na)( Al, Si)4 O8) is a calcium-enriched feldspar mineral first identified in Labrador, Canada, which can display an iridescent effect (schiller). Labradorite is an intermediate to calcic member of the plagioclase series. It ...

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) felds ...

Colors

Spectrolite exhibits a richer range of colors than other labradorites as for instance in Canada or Madagascar (which show mostly tones of blue-grey-green) and high labradorescence.Michael O'Donoghue, ''Gems'', Butterworth-Heinemann, 6th ed., 2006, pp. 238-267, Walter Schumann, ''Gemstones of the World,'' Sterling, 3rd ed., 2007, pp. 52 - 53, 182 Due to the unique colors mined in

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bot ...

, spectrolite has become a

brand A brand is a name, term, design, symbol or any other feature that distinguishes one seller's good or service from those of other sellers. Brands are used in business, marketing, and advertising for recognition and, importantly, to create an ...

name for material mined only there. Sometimes spectrolite is incorrectly used to describe labradorite whenever a richer display of colors is present, regardless of locality: for example, labradorite with the ''spectrolite'' play of colors has sometimes described material from

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Afric ...

History

Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...

Aarne Laitakari (1890–1975) described the peculiar stone and sought its origin for years when his son Pekka discovered a deposit at

Ylämaa Ylämaa (; literally translated the "Highland") is a former municipality of Finland, located in the province of Southern Finland as part of the South Karelia region. It was consolidated with Lappeenranta on January 1, 2010.Salpa Line The Salpa Line ( fi, Salpalinja, literally ''Latch line''; sv, Salpalinjen), or its official name, Suomen Salpa (''Finland's Latch''), is a bunker line on the eastern border of Finland. It was built in 1940–1941 during the Interim Peace betwee ...

fortification A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere ...

s there in 1940. The quarrying of spectrolite began after the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

and became a significant local industry. In 1973, the first workshop in Ylämaa began cutting and polishing spectrolite for jewels. After that, a gem center was established in Ylämaa with training for gem-cutting accompanied by an annual Gem and Mineral Show initiated by Esko Hämäläinen, mayor of Ylämaa municipality.

References

Seppo Lahti I.1989 The origin of interference colours in spectrolite (iridescent labradorite).Geologi 41. Feldspar Gemstones {{silicate-mineral-stub