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Mineral Identification Test (Part 1)

Earth Science Extras

by Russ Colson

Metamorphic rock containing a red mineral that you will identify in this test. Do you notice the lack of cleavage (fracture)? The hexagonal cross section? The prismatic shape? And that color! Are you already forming possibilities in your mind?

So you think you know minerals?

Have you looked at lots of minerals to grow familiar with their appearance and characteristics? Have you learned their observable properties like hardness, cleavage, streak, luster, typical growth habits and common associations of rock type and other minerals?

Then test yourself with the challenges below! Each sample includes a short video in which you can make a number of observations that can help you identify the mineral. The videos are 50-200 MB each, so you will need a fast internet connection. The minerals are somewhat arbitrarily grouped into categories: Whitish Minerals, Blackish Minerals, Brownish Minerals, Shiny Minerals, Clearish Minerals, Reddish Minerals, Other Minerals, and Minerals in Rock Assemblage.

Out of the over 3000 minerals that have been identified and described, we are going to consider only the following list of 60 minerals. Not all of these minerals are represented in this test, and some minerals may appear in the test more than once.

Oxides (and hydroxides):

Cuprite, corundum, hematite, ilmenite, chromite, cassiterite, magnetite, bauxite

Sulfides:

Bornite, galena, sphalerite, covellite, cinnabar, stibnite, arsenopyrite, pyrrhotite, chalcopyrite, pyrite, chalcocite

Sulfates:

Barite, gypsum, anhydrite

Carbonates:

Calcite, siderite, magnesite, dolomite, malachite, azurite

Halides:

halite, fluorite

Phosphates:

apatite, turquoise

Silicates:

nesosilicates: olivine, garnet, andalucite, silliminite, kyanite, staurolite

sorosilicates: epidote

cyclosilicates: beryl, tourmaline

inosilicates: wollastonite, diopside (a pyroxene), augite (a pyroxene), enstatite (a pyroxene), hornblende (a common amphibole)

phyllosilicates: biotite (a mica), phlogopite (a mica), muscovite (a mica), chlorite, lepidolite, talc, kaolinite, serpentine

tectosilicates: quartz, Orthoclase (a feldspar), plagioclase (a feldspar), leucite, nepheline, sodalite

You might want to print out the list above as a handy guide while you try to identify the minerals. The test includes 50 different mineral samples and each video takes around a minute to run. If you are familiar with minerals and their properties already then this test should take you 2-3 hours. The test is broken into three parts. This first part consists of three pages (Whitish Group, Blackish Group, and Brownish Group) with 16 mineral samples.

Have Fun!