Donate now to keep alive!Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on Mindat
What is a mineral?The most common minerals on earthMineral PhotographyThe Elements and their MineralsGeological TimeMineral Evolution
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Definition of schiller

A variable optical phenomenon in gems or minerals, related to sheen; varies from a milky to an almost metallic shimmer to a vivid iridescent play of color. It is usually seen just below the surface in certain varieties of pyroxene, feldspar, etc. Schiller effects are the result of thin microscopic inclusions within a translucent mineral, usually as exsolution lamellae, which refract and reflect incident light. Labradorite, a Na-rich anorthite (a plagioclase feldspar), sometimes exhibits a very pronounced iridescent schiller, also termed labradorescence, in particular where it contains appreciable K. This is due to the presence of a miscibility gap, causing exsolution of orthoclase from the plagioclase host during cooling. Gemstones cut from this material have been termed spectrolite. K-feldspars (probably between microcline and orthoclase in structure) with well developed schiller due to microperthite (exsolution of albite), produce semi-precious gemstones usually known as moonstones. Adularia, a low temperature K-feldspar of variable structure, also can exhibit this milky schiller, also termed adularescence. Sunstone or aventurine feldspar is a variety of feldspar (microcline or oligoclase) that has schiller with an orange/brown background color, and containing small hematite crystals that give it an additional sparkle.

Etymol: German.

Sunstone Norway
Moonstone (Peristerite/albite), Canada
Sunstone Norway
Moonstone (Peristerite/albite), Canada
Sunstone Norway
Moonstone (Peristerite/albite), Canada

See Also: Schillerization, Chatoyancy, Asterism, Iridescence, Labradorescence, Adularescence, Aventurescence, Opalescence, Peristerescence

Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2018, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: March 21, 2018 22:13:50
Go to top of page