15-Minerals and Their Properties

Minerals and Their Properties First lesson in geology. This unit is going to rock! { Lesson 15

Friday, May 23, 2014 What You Will Learn

!You will learn about minerals and their properties. !You will also learn how you can use the properties of different minerals to identify them.

Friday, May 23, 2014 ! Mineral ! Streak ! Luster ! Density ! Mohs scale ! Organic ! Inorganic !

Words3 You Need to Know

Find them and identify each word in writing. 4 What is a mineral?

!All natural earth materials are made of minerals or a combination of minerals. !Minerals are the building blocks of rocks.

Friday, May 23, 2014 Item Minerals Needed to Produce Them ! Carpet Calcium carbonate, limestone ! Glass/Ceramics Silica sand, limestone, talc, lithium, borates, soda ash, feldspar ! Linoleum Calcium carbonate, clay, wollastonite ! Glossy paper Kaolin clay, limestone, sodium sulfate, lime, soda ash, titanium dioxide ! Cake/Bread Gypsum, phosphates ! Plant fertilizers Potash, phosphate, nitrogen, sulfur ! Toothpaste Calcium carbonate, limestone, sodium carbonate, fluorine ! Lipstick Calcium carbonate, talc ! Baby powder Talc ! Hair cream Calcium carbonate ! Counter tops Titanium dioxide, calcium carbonate, aluminum hydrate ! Household cleaners Silica, pumice, diatomite, feldspar, limestone ! Caulking Limestone, gypsum ! Jewelry Precious and semi-precious stones ! Kitty litter Attapulgite, montmorillonite, zeolites, diatomite, pumice, volcanic ash ! Fiberglass roofing Silica, borates, limestone, soda ash, feldspar ! Potting soil Vermiculite, perlite, gypsum, zeolites, peat ! Paint Titanium dioxide, kaolin clays, calcium carbonate, mica, talc, silica, wollastonite ! Concrete Limestone, gypsum, iron oxide, clay ! Wallboard Gypsum, clay, perlite, vermiculite, aluminum hydrate, borates ! Spackling Gypsum, mica, clay, calcium carbonate ! Pencil Graphite, clay ! Carbon paper Bentonite, zeolite ! Ink Calcium carbonate ! Microwavable container Talc, calcium carbonate, titanium dioxide, clay ! Sports equipment Graphite, fiberglass ! Pots and pans Aluminum, iron ! Optical fibers Glass ! Fruit juice Perlite, diatomite ! Sugar Limestone, lime ! Drinking water Limestone, lime, salt, fluorite ! Vegetable oil Clay, perlite, diatomite ! Medicines Calcium carbonate, magnesium, dolomite, kaolin, barium, iodine, sulfur, lithium ! Porcelain figurines Silica, limestone, borates, soda ash, gypsum ! Television 35 different minerals ! 6 Automobile 15 different minerals ! Telephone 42 different minerals

Friday, May 23, 2014 Five Characteristics of Minerals !#1 To be called a mineral, a mineral must occur naturally. It cannot be artificial or man-made. !#2 It must be a solid in nature. !#3 It must have a definite, uniform chemical composition. "Some minerals like gold or silver are made of only one element. Other minerals, like quartz or calcite, are combinations of two or more elements. They made of the same substances linked together in the same way.

Friday, May 23, 2014 !#4 Atoms in minerals are arranged in an orderly pattern or crystals. "Minerals are usually solid crystals. They have a number of flat surfaces in an orderly arrangement. For example, a crystal of quartz is always hexagonal because of the way the atoms of silicon and oxygen join together. ! !#5 Minerals are inorganic. That means they are made up of materials that are not alive and never have been alive.

Friday, May 23, 2014 Identifying Different Minerals

!A mineral can be identified by its physical properties.

Friday, May 23, 2014 Mineral Hardness

! Ability to scratch another mineral ! Measured by the Mohs scale from 1 (talc) to 10 (diamond) ! Quartz (most common mineral and most dust particles) is 7

http://mineral.galleries.com/minerals/elements/diamond/diamond.htm Crystal Shape (Form)

! External structure due to internal arrangement of the atoms ! Six basic groups of shapes, with about three dozen variations

http://www.minerals.net/mineral/carbonat/aragonit/aragoni1.htm ! Describes how light Luster reflects off the surface ! Main categories are “metallic” and “non- metallic” ! Metallic means that it looks like a metal. ! Non-metallic includes “dull,” glassy,” waxy,” “pearly,” and others

http://www.minerals.net/mineral/sulfides/pyrite/pyrite2.htm ! results from ability to absorb some wavelengths and Color reflect others ! some minerals have characteristic colors ! others vary due to chemical differences or impurities (atoms mixed inside the main elements) ! Color depends on whether other substances were present when the mineral formed. http://www.minerals.net/mineral/carbonat/calcite/images/4assortd.htm Streak ! Streak is the color of a mineral in its powdered form. The color of the powder is determined when it is rubbed on a “streak plate” (unglazed porcelain) ! May the be same as mineral as a whole or different ! Pyrite looks golden, but it leaves a greenish- brown streak.

http://www.minerals.net/mineral/oxides/hematite/hematit6.htm Mineral Cleavage/Fracture !Some minerals split along flat surfaces when struck hard--this is called mineral cleavage !Other minerals break unevenly along rough or curved surfaces--this is called fracture !A few minerals have both cleavage and fracture Density (Specific Gravity)

!All minerals have density (mass / volume), but some are very dense !Examples include galena, magnetite, and gold !Density is measured in grams per cubic centimeter g/cm3

http://www.minerals.net/mineral/elements/gold/gold1.htm Special Characteristics-- the “Acid Test” Carbonates react with dilute HCl and other acids by fizzing or bubbling (releasing CO2 gas) Special Characteristics-- Fluorescence

! Some minerals will glow when placed under short-wave or long-wave ultraviolet rays

http://www.sterlinghill.org/Tour%20information.htm Special Characteristics-- Salty Taste

! DO NOT TASTE MOST MINERALS! ! Halite is the exception--it will taste salty

http://mineral.galleries.com/scripts/item.exe?LIST+Minerals+Halides+Halite Special Characteristics-- Magnetism

! Many iron minerals will produce an invisible magnetic force field ! “Lodestone” was used by Vikings more than 1,000 years ago as compasses http://www.minerals.net/mineral/oxides/magnetit/magneti4.htm Hardness and the Mohs Scale !In 1812, Freidrich Mohs, a German mineral expert, developed a hardness scale based on ten relatively common minerals. !The Mohs Scale ranks the hardness of minerals from 1 to 10. 1 is the softest and 10 is the hardest. !The hardness is measured by finding the hardest material that the tested material can scratch or the softest material that can scratch

21the tested material.

Friday, May 23, 2014 On this scale, pencil lead is about a 1, and glass is about a 5.5.

The22 Mohs Scale !hardness !cleavage/fracture ! !crystal shape density (specific (form) gravity) !special properties !luster --reaction to acid !color --fluorescence !streak --salty taste --magnetism

Minerals are identified by their key characteristics 1. Apatite Light Luster = Glassy Hardness = 5.0 Breakage = Uneven Fracture Streak = white Color = green/white Uses = phosphates{ for fertilizers; contains phosphorus for strong bones and teeth Formula = ------Group = Phosphates Specific Gravity =- 3.1 Bauxite Dark Luster = dull/earthy Hardness = 1-3 Breakage = uneven fracture Streak = red Color = red/brown Uses = mined{ for aluminum Formula = AlO Group = Hydroxides Specific Gravity = 3.1 Biotite Mica

Dark: due to Fe and Mg Luster = metallic Hardness = 2.5-3 Breakage: cleavage in sheets Streak = black Uses = decorative{ concrete Formula ------Group = silicates Specific Gravity = 2.7 27

Friday, May 23, 2014