Labradorites (L)

Labradorites  (L)

Labradorites (L) – is an igneous rock of the plutonic depth class, which is a type of anorthosite. In general, anorthosite is a deep igneous rock from the gabroid family, which is more than 90% composed of primary or secondary plagioclase. Another name for anorthosite is plagioclase.
Depending on the composition of plagioclase, among anorthosites there are labradorites, andesinites, bitovnites and anortites. Labradorite is a Labrador variety of anorthosite. It will be recalled that Labrador is a mineral from the group of plagioclase, which contains 50-70% of anortite component (CaAl2Si2O8) and 30-50% of albite component (NaAlSi3O8). Note that the content of plagioclase in some labradorites may be slightly less than 90%. In particular, in Ukrainian labradorites the plagioclase content varies between 72-97%, ie we have a very gradual transition from labradorite to gabbro. Therefore, for leukocratic gabbroids with a plagioclase content of 75-90%, usually use the name gabbro-labradorite or gabbro-anorthosite.
The most common minor minerals of Labradorites are rhombic and monoclinic pyroxenes. Olivin, amphibole, biotite, K-Na feldspar, quartz and calcite are also characteristic of some differences. In accessory quantities, the composition of labradorites may include apatite, ilmenite, magnetite, pyrite, pyrrhoti

Все
🎫
🇬🇧 🎫
🇺🇦 🎫
🇺🇦
🇬🇧