An endmember (also end-member or end member) in mineralogy is a mineral that is at the extreme end of a mineral series in terms of purity of its chemical composition. Minerals often can be described as solid solutions with varying compositions of some chemical elements, rather than as substances with an exact chemical formula. There may be two or more endmembers in a group or series of minerals.
For example, forsterite (Mg
2SiO
4) and fayalite (Fe
2SiO
4) are the two end-members of the olivine solid-solution series, varying in Mg2+
and Fe2+
in their chemical composition. So, the chemical formula of olivine can be better expressed as Mg(2−x)FexSiO4 or MgxFe(2−x)SiO4.
As another example, the tectosilicate feldspar can be described as a solid solution of the endmembers K-feldspar (KAlSi
3O
8), albite (NaAlSi
3O
8) and anorthite (CaAl
2Si
2O
8).[1] A specific feldspar can have varying quantities of potassium (K), sodium (Na) and calcium (Ca).
See also[edit]
References[edit]
- ^ What is Feldspar? Archived 2008-02-15 at the Wayback Machine Industrial Minerals Association. Retrieved on February 9, 2008.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction