Minerals

Minerals are naturally occurring, solid, crystalline, inorganic substances with a definite chemical composition.

Minerals Minerals might be made of one element, such as: – Gold – Silver – Copper – Diamond

Minerals …but most minerals are made of more than one element combined together: – Ruby = Al 2 O 3 + Cr – Emerald = Be 3 Al 2 (SiO 3 ) 6 – Feldspar = KAlSi 3 O 8 – NaAlSi 3 O 8 – CaAl 2 Si 2 O 8 – Sapphire = Al 2 O 3 + V, Ti, or Fe (for purple, white, or yellow/green) – Halite = NaCl

Minerals Most minerals end in the word “ite” to identify it as a mineral. – Malechite – Hematite – Magnetite – Pyrite – Halite – Graphite – Wolframite

Minerals There are about 3700 different types of minerals on the earth that we know of, and about 100 new minerals are discovered each year.

Minerals The most common minerals on earth are: – Quartz (most common on Earth’s surface) – Feldspar (most common, in crust, but is a combination of several different types of minerals.) – Olivine (Most common in the mantle)

Minerals The most rare minerals in the Earth are: – PAINITE (18 exist) – SERENDIBITE – POUDRETTEITE – GRANDIDIERITE – JEREMEJEVITE – RED BERYL – TAAFFEITE – BENITOITE

Birthstones Most birth “stones” are actually minerals. Some months have a birthstone and a birth gemstone because not all minerals work well for jewelry

Mineral properties Minerals are identified by the properties that they have. Just like each element has it’s own set of properties that help identify it, each mineral has it’s own properties.

Minerals - properties Luster tells how well a mineral reflects light. A minerals luster might be: – Metallic (shiny like a metal) – Nonmetallic (not very shiny) Waxy Vitreous (glassy) Pearly Oily Adamantine (brilliant like diamond)

Minerals - properties Hardness describes how hard it is to scratch the mineral. The Moh’s hardness scale is used to find the hardness of a mineral.

Minerals - properties Cleavage describes how the mineral breaks. (Does it break along certain planes?)

Minerals - properties Color is important in identifying most minerals. RubySapphire

Minerals - properties But color can be deceptive

Minerals - properties Streak is the color that the mineral is when it is a powder. A streak plate is used to find a minerals streak color.

Minerals - properties Other properties that might be used to identify minerals include: – Magnetism (tiny bits of magnetite in migrating birds) – Reaction with certain chemicals – Smell – Taste – Flourescence – Crystal structure

Minerals  Rocks Minerals combine to form rocks Mineral + mineral = rock

Rocks Rocks don’t have a definite chemical composition like minerals do because they’re made of lots of “pieces” of different minerals all hooked together.

Rocks There are 3 main types of rocks: – Sedimentary – Igneous – Metamorphic