schist - greenschist facies of the Pelona schist - unit of 5 student specimens

This attractive grayish green schist is mapped as a greenstone schist, has an uneven foliated parting, is composed of chlorite, epidote and albite feldspar. Schists vary greatly in composition and appearance. They are often derived from clays and muds and shales and fit into a metamorphic sequence of slate, phyllite, schist and gneiss in order of increasing metamorphosis. They can also be derived from fine grained igneous rocks. This schist, a unit of the Pelona Schist, was metamorphosed from silica poor igneous rocks. The specimens were collected in San Antonio Canyon, San Gabriel Mountains, Los Angeles County, California. Mica schists are the most common, with the mica making a schist easy to recognize. The Pelona Schist is quite variable. These specimens are distinctly green (for a rock - and not green like your lawn). Schists have at least 50% of the mineral grains in alignment. If less than 50%, the rock is a gneiss. This rock can be cleaved or split along layers, illustrating the origin of its name, from the Greek skhistos for can be split. Schists are often described by their dominant mineral such as garnet schist or biotite schist. Chlorite schist is largely composed of chlorite - Greek chloros = green. The photo is representative of what we ship. Shipping: By Priority Mail or USPS Ground Advantage, whichever is cheaper, unless we find a better rate. Click > here < for shipping rates. See comment at Note! Use back button to return to this page. Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with combined shipping. A link in that invoice will bring you back to checkout, no hassle.