What is a MINERAL? Chapter 3 – Minerals of the Earth A mineral is SOLID NONLIVING (inorganic) material found in the Earth naturally occurring Definite chemical makeup Definite crystalline structure 6 min What is a Mineral? Geology Kitchen 1

What is a MINERAL? Elements Smallest building blocks of matter Natural substance Cannot be broken down into simpler substances

Minerals Most of the minerals of the Earth’s crust are made up of only 8 elements. Most common elements - Oxygen Silicon Aluminum

Minerals Cannot be formed from a living thing - inorganic Found in nature Solid

Feldspar Most common mineral in Earth’s crust Silicon, aluminum, & oxygen

Quartz 2 nd most common mineral in Earth’s crust Silicon & oxygen

Crystals Elements are arranged in a regular pattern

Groups of Minerals Based on chemical composition Silicate MineralsNonsilicate Minerals Dioptase is hydrous copper silicate, CuSiO 2 (OH) 2. It usually occurs in bright green crystals in the oxidized zones of copper deposits.

Silicate Minerals Made of silicon, oxygen, potassium & aluminum Makes up more than 90% of the Earth’s crust Quartz – basic building blocks of many rocks 3 ½ min Silicates Minerals Photos & music Silicates! Color description and Hardness

Feldspar – main component of most rocks Silicate Minerals

Mica – separate easily into thin sheets

Nonsilicate Minerals Mostly made up of carbon, oxygen, fluorine & sulfur Native elements – composed of only ONE element Copper Gold Silver 5 min Non silicates Minerals Photos & music only

Nonsilicate Minerals Carbonates – Calcite – used in cement/concrete

Nonsilicate Minerals Halides – salts – sodium chloride, fluorite Halite – table salt Fluorite

Nonsilicate Minerals Oxides – Corundum - ruby & sapphire (gemstones) Corundum with calcite Ruby is the red variety of the corundum mineral, one of the hardest minerals on Earth which also includes Sapphire. Pure corundum is colorless.

Nonsilicate Minerals Sulfates – gypsum – used in toothpaste, sheetrock & paint

Nonsilicate Minerals Sulfides – galena (lead ore) – used in batteries & medicines Blue Fluorite with a mirror-like Galena cube sitting atop Quartz matrix

Georgia’s State Mineral Staurolite was designated the official state mineral of Georgia in Commonly called “fairy crosses” or “fairy stones,” staurolite crystals are common in northern Georgia and are collected as good luck charms.

Identifying Minerals COLOR Easy to observe but not reliable Green Garnet Cavansite Rhodonite Tremolite ½ min Identifying Minerals – Geology Kitchen 2

Identifying Minerals STREAK Color of mineral in its powdered form By rubbing a mineral across a porcelain tile – it leaves a stripe of color 2 Hematite looks black but leaves red-brown streak. Pyrite looks yellow-gold but leaves a gray streak.

Identifying Minerals LUSTER is the way a mineral reflects light Can be dull, shiny, greasy, pearly, metallic, or glassy 3 Garnet is glassy.Pyrite is metallic. Talc is greasy.

Identifying Minerals CRYSTALS Minerals have different shape or crystal structure The way crystals are arranged – breaks differently 4 CLEAVAGE – breaks smoothly along a flat surface FRACTURE – breaks along uneven surfaces - irregular Obsidian Olivine

Identifying Minerals HARDNESS Each mineral has a distinct hardness MOHS Scale is based on ten common minerals. A harder mineral will scratch a softer mineral. 5 Talc – softest Diamond - hardest

Special Properties Calcite reacts to simple acid by bubbling. Magnetite contains iron and is magnetic. Fluorite glows under ultraviolet light (black light). Halite has a salty taste.

Uses of Minerals ORE is a natural mineral deposit large enough and pure enough to be mined for a profit. Iron ore is mixed with carbon to make steel.

Aluminum (mineral) comes from the ore bauxite. Uses of Minerals

Graphite – pencil “lead” Uses of Minerals Quartz – used to make glass. The basic ingredient of glass is silica, which is derived from quartz sand. The silica is heated until it melts, shaped and then rapidly cooled.

Uses of Minerals Gemstones nonmetallic minerals highly valuable for their beauty and rarity COLOR is the most important characteristic for a gemstone. 3 min Top 10 Rarest Gemstones

Epsomite - mineral Ellison’s Cave – Walker County, GA 2 ½ min Ellison’s Cave Rescue 2 min photos of Ellison’s cave

PowerPoint Presentation 2013 M. Brumbaugh - TCMS Chapter 3 – Minerals of the Earth 1 ½ min How to grow your own Chemical Garden 4 min Birthstones and their meanings 4 min What is your Birthstone? 4 min Diamonds – From Mine to Market 3 min Rocks and Minerals 5 min Digging for Amethyst in Australia 9 min The Crystal Collector: "Giant quartz crystals 3 min How to Find Gemstones