Editing Spectrolite

{{Short description|Variant of labradorite ((Ca,Na)(Al,Si)⁴O⁸)}}
[[File:LabradoriteOslo.jpg|250px|right|thumb|Spectrolite from [[Ylämaa]], Finland]]
[[File:Spectrolite1.jpg|250px|right|thumb|Polished spectrolite showing the color play]]
'''Spectrolite''' is an uncommon variety of [[labradorite]] [[feldspar]].

== 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]].<ref name="Gems">Michael O'Donoghue, ''Gems'', Butterworth-Heinemann, 6th ed., 2006, pp. 238-267, {{ISBN|0-7506-5856-8}}</ref><ref name="Schumann">Walter Schumann, ''Gemstones of the World,'' Sterling, 3rd ed., 2007, pp. 52 - 53, 182 {{ISBN|1-4027-4016-6}}</ref>  Due to the unique colors mined in [[Finland]], spectrolite has become  a [[brand]] 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]].<ref name="Gems" />

== History ==
[[Finland|Finnish]] [[geologist]] Aarne Laitakari (1890–1975) described the peculiar stone and sought its origin for years when his son Pekka discovered a deposit at [[Ylämaa]] in south-eastern Finland, while building the [[Salpa Line]] [[fortification]]s there in 1940.  

The quarrying of spectrolite began after the [[Second World War]] 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.
{{Reflist}}

[[Category:Feldspar]]
[[Category:Gemstones]]


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