Bytownite is a calcium rich member of the plagioclase solid solution series of feldspar minerals. It is usually defined as having "%An" between 70 and 90. Like others of the series, bytownite forms grey to white triclinic crystals commonly exhibiting the typical plagioclase twinning and associated fine striations. Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... A binary phase diagram displaying solid solutions over the full range of relative concentrations. ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... Minerals are natural compounds formed through geological processes. ... Anorthite is one of the plagioclase feldspars, an important group of minerals abundant in the Earths crust. ... In crystallography, the triclinic crystal system is one of the 7 lattice point groups. ... It has been suggested that twin boundary be merged into this article or section. ...

The specific gravity for bytownite varies between 2.74 and 2.75. The refractive indices ranges are nα=1.563 - 1.572, nβ=1.568 - 1.578, and nγ=1.573 - 1.583. Precise determination of these two properties with chemical, X-ray diffraction, or petrographic (birefringence and optic angle) analysis are required for identification. Relative density (also known as specific gravity) is a measure of the density of a material. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of x-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ... Petrography is the description of rocks and their textures. ... A calcite crystal laid upon a paper with some letters showing the double refraction Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals, depending on...

Bytownite occurs in gabbro intrusions and in metamorphic complexes. The mineral was first described in 1835 and named for an occurrence at Bytown (now Ottawa), Canada. Gabbro specimen. ... Pluton redirects here. ... Metamorphism can be defined as the mineralogical, chemical and crystallographic changes in a solid-state rock, i. ... Motto: Template:Unhide = Advance Ottawa/Ottawa en avant Location City Information Established: 1850 as Bytown Area: 2,778. ...

References

• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., Wiley, ISBN 0471805807
• Mindat with locations
• Mineral galleries
• Webmineral data