Leave a message
Fri
14
Oct

Click Here For Best Selection Of High Quality Polarizing Microscope

Click Here For Best Selection Of High Quality Polarizing Microscope

The chemical composition of mineral Johnsomervilleite is indicated by the formula Na2Ca(Mg,Fe++,Mn)7(PO4)6. Johnsomervilleite is considered as an accessory mineral in podiform metamorphic segregations in kyanite-sillimanite-grade gneiss. This mineral is commonly found from its type of locality at Glen Cosaidh, Loch Quoich,, Inverness-shire, Scotland. Johnsomervilleite was named for John M. Somerville (1908-1978), who collected the first specimen. Mineral Johnsomervilleite is known to crystallized in the trigonal system of crystal formation. Mineral Johnsomervilleite is commonly found showing perfect cleavage in one direction which is more clearly exhibited when viewed with the aid of polarized microscope used in the field of optical mineralogy. This mineral is usually found dark brown or blackish gray in hand sample. The density measure of this mineral is usually found 3.35 grams per cubic centimeters. Most crystals are found transparent to translucent in appearance. Johnsomervilleite is also commonly found exhibiting brittle to splintery fracture. This brittle fracture is commonly found leaving splintery fragments. The crystal habit of mineral as described in the field of optical mineralogy usually includes colloform crystals forming from a gel or colloidal mass. It can be also found dendritic with branching “tree-like” growths of great complexity similar to pyrolusite. Sometimes it can be also found in granular form. This is generally occurring as anhedral to subhedral crystals in matrix. The hardness measure of mineral Johnsomervilleite is usually found 4.5 when evaluated using the Mohs scale method. Mineral Johnsomervilleite is usually found showing vitreous or glassy luster when evaluated in reflected light of polarizing microscopes used in the field of optical mineralogy. Mineral Johnsomervilleite is usually found leaving a light brown streak when rubbed on whie porcelain streak plate. Mineral Johnsomervilleite is commonly found showing uniaxial figure when evaluated between crossed nicols of polarizing microscopes used in the field of optical mineralogy. Mineral Johnsomervilleite is also found not radioactive.



Author:
Time:
Friday, October 14th, 2011 at 7:21 am
Category:
Optical Mineralogy
RSS:
You can follow any responses to this entry through the RSS 2.0 feed.
Navigation:
Click Here For Best Selection Of High Quality Polarizing Microscope