MATTER AND MINERALS Earth’s Treasure

MINERALS The study of minerals is Mineralogy. The first minerals discovered were flint and chert. These minerals were used in weapons and cutting tools. Minerals such as gold, silver, and copper were mined by the Egyptians back in 3700 B.C. Bronze, a alloy, is a combination of copper and tin.

MINERALS A mineral is defined as any naturally occurring inorganic solid that possesses an orderly crystalline structure and a definite chemical composition that allows for some variation. A mineral has the following characteristics: Naturally occurring – of geologic process Generally inorganic – found naturally in the ground Solid substance – in solid form Orderly crystalline structure – repeating pattern within Definite chemical composition – ratio of atoms expressed by a chemical formula. (SiO2 – quartz)

MINERALS A rock is defined as a solid mass of minerals or aggregates of minerals.

ATOMS WITHIN MINERALS All matter including minerals are made of atoms. An atom is the smallest particle of an substance that cannot be chemically split. Atoms contain 3 subatomic particles: Proton – positive charge Neutron – no charge Electron – negative charge The atom has an overall neutral charge.

ATOMS WITHIN MINERALS Atoms combine through their outermost electrons or valence electrons. These electrons allow compounds to be made. For example:

ATOMS WITHIN MINERALS Atoms are defined by their atomic number. This number gives the number of protons and electrons. Again, the atom has an overall neutral charge. A group of the same atoms make up an element. Elements are arranged on a periodic table. Each element is denoted by a chemical symbol, either one letter or two, with the first letter always capitalized. Different atoms join together to form chemical compounds.

ATOMS AND BONDING Atoms bond to form compounds. They also bond to become more stable through attraction of electrical forces that hold atoms together and bond them to each other. . A chemical bond is a transfer or sharing of electrons that allows each atom to attain a full valence shell of electrons. There are 2 types of bonds: IONIC BOND: transfer COVALENT BOND: sharing

ATOMS AND BONDING IONIC AND COVALENT

ATOMS AND BONDING VALENCE ELECTRONS

MINERAL PROPERTIES Minerals have unique physical and chemical properties. These properties are: Optical Crystal shape (Habit) Mineral Strength Density and Specific Gravity

MINERAL PROPERTIES Optical Properties Luster- ability to reflect light Types of Luster include: Metallic –ability to have the appearance of metal regardless of color. Submetallic – dull metal appearance Nonmetallic- vitreous or glassy Dull or Earthy – appearance of soil Pearly – appearance of a pearl Silky – appearance of satin Greasy – appearance of being coated in oil.

MINERAL PROPERTIES Optical Properties Minerals have the ability to transmit light. Opaque – no light transmitted Translucent – light is transmitted, no image. Transparent – light and an image is transmitted

MINERAL PROPERTIES Color and Streak Color is the most general characteristic of rocks. Streak is the color of a mineral in powered form. Streak can help distinguish between metallic and nonmetallic luster.

MINERAL PROPERTIES Crystal Shape (Habit) Crystal shape or Habit is used to describe the characteristic shapes of individual crystals or aggregates of crystals. Words used to describe the shape are: Equant Bladed Fibrous Tabular Prismatic Platy blocky Banded Granular Botryoidal

MINERAL PROPERTIES Mineral Strength How easily minerals break under stress is determined by the type and strength of the chemical bonds that hold the crystals together. Terms used are: Hardness – a measure of the resistance of a mineral to abrasion or scratching Cleavage – the tendency a mineral to break along planes of weak bonding. Fracture – minerals that have chemical bonds that are equally strong in all directions.

MINERAL PROPERTIES Density and Specific Gravity Density is the mass per unit volume of a substance or object. Specific Gravity – a number representing the ratio of a mineral’s weight to the weight of an equal volume of water. Most minerals have a specific gravity between 2 and 3.

MINERAL PROPERTIES Other Properties Taste Feel Double Refraction Chemical test for Carbonates using HCL

MINERAL GROUPS

MINERAL GROUPS

MINERAL GROUPS Minerals Uses

RESOURCES Renewable vs Nonrenewable Renewable resources can be replenished over relatively short time spans. An example is using forest products for lumber and paper. Trees can be replanted. Nonrenewable resources are totally the opposite.

RESOURCES Mineral Resource vs Ore Deposit Every product manufactured contains materials obtained from minerals. There are two types of resources: Mineral resource- occurrences of useful minerals that are formed in such quantities that eventful extraction is reasonably certain Ore deposit- naturally occurring concentration of one or more metallic minerals that can be extracted economically.