Minerals

Agenda Notes Practice Worksheet

What is a mineral? Definition: A mineral is a naturally formed, inorganic solid that has a definite crystalline structure.

What is a mineral? Solid Naturally Occurring Inorganic Properties: Solid Cannot be a liquid or a gas Naturally Occurring Found in nature, not man-made Inorganic Is not alive and never was, non-living Fixed composition Has a chemical formula, most are formed from compounds of two or more elements, some minerals consist of one element ex. Au Crystal Form A definite structure in which atoms are arranged

The next few slides show an assortment of items. Questions to ask yourself when determining if an item is a mineral or not: Is it non-living material? Is it a solid? Is it formed in nature? Does it have a crystalline structure? The next few slides show an assortment of items. As a group, categorize the items as either: Minerals or Non-Minerals.

Wood

Gold

Fossil

Topaz

Bones

Granite

Quartz

Pearls

Talc

Diamond

Coal

Rock Salt

And the answers are… Minerals Non-Minerals Gold Topaz Quartz Talc Diamonds Non-Minerals Wood - once living Fossils – once living Bone - living material Granite - intrusive igneous rock Pearls – made by oysters Coal - Sedimentary rock Rock Salt – Sedimentary rock

Minerals vs Rocks Rocks are made of more than 1 mineral Minerals are formed some of the same ways as rocks Cooling of Magma Precipitation from Water Heat and Pressure Hydrothermal Solutions

Gemstones Gemstones are minerals or rocks that are rare and considered precious (pretty in appearance). When cut and polished, it is used for jewelry.

Identifying Characteristics of Minerals Color Streak Luster Cristal Form Hardness Cleavage Fracture Density

Color  Small amounts of different elements can give the same mineral different colors.

Streak  Streak is the color of a mineral in its powdered form.

Luster  Luster is used to describe how light is reflected from the surface of a mineral.

Crystal Form  Crystal form is the visible expression of a mineral’s internal arrangement of atoms.

Hardness  Hardness is a measure of the resistance of a mineral to being scratched. Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest). Items higher on the scale can scratch items lower on the scale

Cleavage  Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces.

Fracture  Minerals that do not show cleavage when broken are said to fracture.  Fracture is the uneven breakage of a mineral

Density  Density is a property of all matter that is the ratio of an object’s mass to its volume.

Distinctive Characteristics  Some minerals can be recognized by other distinctive characteristics such as - magnetic - radioactive - chemical reaction - taste