EES 9 - Minerals

Silicates are the most common rock-forming minerals on Earth. All silicate minerals include the silica tetrahedron (pictured below). Label the ball and stick model with the correct elements that form the silica tetrahedron. You may need to use some labels more than once.

- The atoms of a silica tetrahedron are held together by covalent bonds. - Silicon is at the center of the silica tetrahedron. - Oxygen forms the outer boundary of the silica tetrahedron.

Various physical characteristics of minerals are used to identify unknown specimens. Match the test name with the appropriate description.

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Specific gravity

density relative to water Because of differences in chemical composition, some minerals will feel more dense than others.

Cleavage

how a mineral breaks Minerals can have one, two, or three planes of cleavage.

Hardness

susceptibility/resistance to scratching Hard minerals can still break; they are just difficult to scratch.

Streak

the color of a mineral's powder Streak will not always be the same color as the mineral.

Luster

the way a mineral scatters light Common types of luster include metallic, vitreous, earthy, or silky.

The properties of a mineral are the result of the chemical bonds that hold the elements within a mineral together. Drag and drop the name of the bond to the correct bonding schematic.

- An ionic bond forms when an electron is removed from one atom and added to a second. - In covalent bonds, atoms share electrons. - In metallic bonds, nuclei and inner shells of electrons float in a "sea" of free electrons.

Below are six examples of mineral chemical compositions. Match the chemical formula with the correct mineral class.

Carbonates - CaCo3 Carbonates have CO32- as the anion. Silicates - SiO4 Si (silicon) is the primary constituent of silicate minerals. Sulfides - PbS Minerals with S (sulfur) are called sulfides. Oxides - Fe3O4 Minerals containing metal cations, like iron (Fe), bonded to oxygen (O) are called oxides. Halides - NaCl Halides include halogen anions such as chloride (Cl-). Native Metals - Au Pure gold is a native metal.

A cation is a positively charged ion. An anion is a negatively charged ion. Below are six common mineral-forming cations and anions. Place each ion into the correct grouping.

Cation: - magnesium Magnesium has a +2 charge. - sodium has a +2 charge -calcium has a +2 charge Anion: - chloride Chloride has a −1 charge. - Fluoride Fluoride has a −1 charge. - oxygen Oxygen has a −2 charge.

Minerals are the building blocks of our geological world. Select the features that are true of all minerals.

Minerals: - crystalline solid Each mineral has a crystal lattice and exists as a solid. - inorganic All minerals are inorganic. - naturally occurring Artificial materials, such as plastics, are not minerals. - definable chemical composition Any mineral, anywhere in the world, will have the same chemical formula. Not Features True of ALL Minerals: - can be solid, liquid or gas Elements can be found in solid, liquid, or gas phases, but minerals are only found as solids. - organic - form underground Many minerals form underground, but minerals can also form at the surface of the Earth as water evaporates.