| 词条 | Spectrolite |
| 释义 |
Spectrolite is an uncommon variety of labradorite feldspar. Spectrolite exhibits a richer range of colors than labradorite (that shows only tones of blue-grey-green) and high labradorescence.[1][2] Spectrolite was initially a brand name for material mined in Finland, but is sometimes 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 also reported from Madagascar.[1] The difference between Finnish spectrolite and other labradorites is that crystals of the former have considerably stronger colourfulness than other labradorites, caused by the black base color of spectrolite feldspar; other labradorites have mostly a transparent base color. Spectrolite is often cut as a lapidary cabochon, similar to plain labradorite, to enhance the effect and is used as a gemstone. Finland deposit{{Unreferenced section|date=July 2009}}Finnish geologist Aarne Laitakari (1890–1975) had 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 fortifications there in 1940. The Finnish stone exhibits a uniquely vivid iridescence and a full spectrum of colors, hence the name "spectrolite" was coined by the elder Laitakari. The quarrying of spectrolite began after the Second World War and has become a significant local industry. In 1973 the first workshop in Ylämaa began cutting and polishing spectrolite for jewels. ReferencesSeppo Lahti I.1989 The origin of interference colours in spectrolite (iridescent labradorite).Geologi 41. 1. ^1 Michael O'Donoghue, Gems, Butterworth-Heinemann, 6th ed., 2006, pp. 238-267, {{ISBN|0-7506-5856-8}} {{silicate-mineral-stub}}2. ^Walter Schumann, Gemstones of the World, Sterling, 3rd ed., 2007, pp. 52 - 53, 182 {{ISBN|1-4027-4016-6}} 2 : Feldspar|Gemstones |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。