Minerals and Mineral Families

What is a Mineral? A substance found in the Earth that always has the same chemical composition

What is a Mineral? I - S - O - D - A - Inorganic Solid Occurs naturally Definite chemical composition Atoms in a pattern

Review ?? Is water a mineral? Why or why not? No because it is a liquid ?? Is coal a mineral? Why or why not? No because it is made from living things. (plants)

Only 8 elements make up 98.5% of the Earth. Oxygen Silicon Aluminum Iron Calcium Sodium Potassium Magnesium The 2 most common elements in the crust. More than 90% contain Si and O

How do minerals form? Magma or lava cools and mineral compounds form.

How do minerals form? Water containing dissolved ions slowly evaporates

How do minerals form? Existing minerals are changed by heat and pressure

What do minerals look like? When atoms in a mineral line up in an orderly pattern a crystal forms. A crystal is a geometric solid with smooth sides or faces

Cubic Crystals All sides are equal length All sides meet at 90°

Orthorhombic Crystals All sides are unequal in length All sides meet at 90°

Tetragonal Crystals 2 sides are equal length 1 side is longer than others All sides meet at 90°

Hexagonal Crystals Six sided crystals Sides meet at 60°

Monoclinic Crystals All sides are unequal in length Two sides meet at 90°

Triclinic Crystals All sides are unequal in length. No sides meet at 90°

Review ?? What determines which crystal shape will form? The internal arrangement of the atoms ??Why are perfect crystals not commonly found in nature? There is not enough room for them to grow

What kinds on minerals exist in Earth’s crust? Minerals can be divided in 7 groups or families Family NameCommon Elements Examples SilicatesOxygen and silicon Quartz, feldspar

What kinds on minerals exist in Earth’s crust? Family NameCommon Elements Examples CarbonatesOxygen, carbon and a metal Calcite, dolomite

What kinds on minerals exist in Earth’s crust? Family NameCommon Elements Examples OxidesOxygen and a metal Hematite, magnetite

What kinds on minerals exist in Earth’s crust? Family NameCommon Elements Examples SulfidesSulfur and a metal Pyrite

SULFATES CONTAIN SULFUR AND OXYGEN SO 4 EXAMPLES GYPSUM

HALIDES CONTAIN an ELEMENT PLUS Cl, Br, and F

NATIVE ELEMENTS

WHICH MINERAL FAMILY? FeCO 3 Mg 2 SiO 3 HgS Ag MgSiO 3 Al 2 O 3 Cu 2 CO 3 (OH) 4 KCl

PHYSICAL PROPERTIES HARDNESS – HOW EASILY IT CAN BE SCRATCHED LUSTER – HOW IT REFLECTS LIGHT COLOR – LEAST RELIABLE STREAK – COLOR OF ITS POWDER CLEAVAGE/FRACTURE FLORESCENCE, MAGNETISM, ODOR

Review ?? What is one way minerals can form? Water containing dissolved ions slowly evaporates Magma or lava cools and mineral compounds form Existing minerals are changed by heat and pressure

Review ??What are the 2 most abundant minerals in the crust? Oxygen and silicon ?? What family do they belong to? Silicates

Review ?? What determines the shape of a mineral? The internal arrangement of atoms

Review ??What are the 5 things that define a mineral? Inorganic Solid Occurs naturally Definite chemical composition Atoms in a pattern

Review ?? How are minerals identified? By their physical properties