Generalized Rock Identi˜cation Chart For Common METAMORPHIC ROCKS TEXTURE GRAIN SIZE INTERPRETATIONS DESCRIPTION very ˜ne ROCK NAME Common Protoliths Metamorphic Grade / Type SLATE PHYLLITE SCHIST GNEISS METACONGLOMERATE METABASALT HORNFELS ANTHRACITE COAL mudstone mudstone volcanic rocks, …

METAMORPHIC ROCK IDENTIFICATION CHART Texture Grain size Minerals Name Very fine quartz, silicate minerals Hornfels Medium-Fine quartz Quartzite Coarse to fine calcite Marble Very fine micas microscopic clays Slate Fine micas tiny micas Phyllite Medium-Large micas micas, often with garnets Schist Bands of coarse mica and feldspar

Varieties of schists and gneisses are subdivided on the basis of their mineral composition, which is determined largely by the composition of the original rock, the “grade” or intensity of metamorphism, and the kinds of chemical substances either …

Metamorphic rocks are typically classified first by their texture and then by their mineral composition and protolith (the rock type they formed from). Identifying a metamorphic rock can sometimes be very challenging, so it helps to know what metamorphic rocks typically look like.

May 17, 2017 · Metamorphic rocks are rocks that have undergone a change from their original form due to changes in temperature, pressure or chemical alteration. The classification of metamorphic rocks is based on the minerals that are present and the temperature and pressure at which these minerals form.

Medium to coarse grained; grain size will generally increase with metamorphic grade: Muscovite, biotite, chlorite, talc, garnet, kyanite, staurolite, feldspar, quartz, tourmaline, and many others

metamorphic rocks is that they have been changed from their original rock through heat and pressure. Metamorphic rocks are divided into two categories: foliated and nonfoliated. Foliated refers to repetitive layering or banding in metamorphic rocks. Each layer may be as thin as a sheet of paper, or over a meter in thickness.

Metamorphic rocks form just that way- by changing (meta= to change) form (morph= form). These rocks start out as igneous or sedimentary rocks (or metamorphic) and are altered or rearranged by a combination of heat and pressure. Simply put, metamorphism occurs when a previously existing rock, the parent rock, is

Two of the most common properties to determine classification of a rock are hardness and reaction with dilute hydrochloric acid (see Hardness And Acid Reaction Tests). The Key To Common Metamorphic Rocks allows identification of a rock based on its physical properties. We are able to do this because the properties do not overlap completely.

Rock is glassy or bubbly (has small holes). The rock is igneous (basalt or pumice). b. Rock has hard, flat sheets that split off. The rock is metamorphic (slate). c. Rock is soft and may be layered. The rock is sedimentary (shale). d. Rock is black, soft, brittle, shiny in places. The rock is sedimentary (coal). 5. a.