PAPA+4.1

toc =__Properties of Minerals__=

__Vocabulary__

 * inorganic**- the mineral can't come from an organism
 * crystal**- the solid made up of atoms from an inorganic thing
 * element**- something made up of one part of electrons, protons, and a nucleus
 * compound**- parts of electrons and protons that are stuck together
 * Moh's Hardness Scale**- something that puts minerals in places depending on their toughness
 * streak**- the color of the particles left by rubbing the inorganic solid against a streak plate
 * luster**- something that means how much the inorganic solid shines
 * cleavage**- an inorganic organism that breaks in two on something smooth
 * fracture**- how a inorganic organism appears when it splits in a weird form
 * fluorescence**- an inorganic organism that shines below a super shining light

Intro

 * In a museum
 * find hall of minerals
 * find minerals like sphalerite
 * sphalerite makes tin cans and computer chips

What is a Mineral

 * Many Minerals
 * more than 3,000
 * only 100 are common
 * 20 minerals make up the earth's crust
 * rock forming minerals
 * To be a mineral it must be...
 * naturally occurring, inorganic, solid, crystal structure, and a definite chemical composition
 * Naturally occurring
 * minerals mus occur naturally
 * cement, brick, steel are all man made
 * Inorganic
 * can't come from parts of a living thing
 * coal comes from plant remains and animals remains that lived long time ago
 * Solid
 * has a definite volume and shape
 * all materials are packed tightly
 * Crystal Structure
 * mineral particles line up in a pattern that repeats
 * this makes a crystal
 * crystal has flat sides (faces) that have sharp edges and corners
 * crystal structure can be noticeable or hard to recognize
 * few minerals don't have crystal structures but are still minerals
 * opal
 * Definite Chemical Composition
 * minerals contain definite elements
 * elements are substances composed of a single atom type
 * almost all elements are compounds
 * compounds are made of two or more elements
 * The elements that make th compound are chemically connected
 * quartz crystal has 1 atom of silicon for every 2 atoms of oxygen
 * some elements appear as them selfs with nothing else
 * like copper, silver, god are minerals

Identifying Minerals

 * 1849 - Gold Rush
 * 1,000s of people went west for gold in the California hills
 * some found gold, some found fools gold
 * There are so many minerals that identifying them is difficult
 * each mineral has its own properties
 * some easy to tell, some hard
 * 7 tests to tell
 * hardness, color, streak, luster, density, crystal systems, cleavage and fracture
 * Hardness
 * scale called Moh's Hardness scale
 * measures ten mineral's hardness from softest to hardest
 * a mineral can scratch any mineral softer than itself
 * to find the hardness of a mineral that isn't on the list, test it by scratching it with minerals that are on the list
 * such as sphalerite, a 4 on the scale because it can be scratched by Apatite
 * Color
 * easy to identify property
 * color cannot tell you what many minerals are, but some can
 * such as malachite (always green), and azurite (always blue)
 * many minerals come in varieties
 * Streak
 * streak is the color of the minerals power
 * you can observe a streak by rubbing a mineral by a special tile called a streak plate
 * streak color an mineral color often vary
 * for example, pyrite has a gold color with a greenish-black streak
 * real gold makes a golden-yellow streak
 * Luster
 * luster is how a mineral's sides reflects light
 * metal minerals are shiny like galena and unlike the mineral malachite
 * some like quartz, have a glassy luster
 * some are earthy, wavy, and pearly
 * Density
 * density is the mass in a given space (mass per unit volume)
 * no matter what the size, the density is always the same
 * to compare density, just lift minerals and whichever is heavier has more density
 * if you compare quarts and galena of the same size, galena will be 3x heavier
 * this only provides a rough measure of density
 * scientists use a balance or water displacement
 * Crystal Systems
 * crystals of each mineral grows by atom to make a crystal structure
 * these structures are based in 6 categories called the crystal systems.
 * halite is cubic
 * sometimes a mineral and crystal structure are the same
 * depending on how much space the crystal has, it can be formed perfectly or imperfectly
 * Cleavage and Fracture
 * the way a mineral breaks can identify it
 * a mineral that splits easily along flat surfaces has cleavage
 * this depends on crystal arrangement (depending how the atoms are arranged), it may break easily from some sides than others
 * mica breaks in sheets, feldspar splits at right angles
 * most minerals don't split evenly, therefore it is fracture
 * quartz has a curved shell-like fracture
 * metals form jagged points
 * Special Properties
 * some minerals glow under ultra-violent light, this is called fluorescence
 * like scheelite
 * In some minerals, magnetism occurs randomly
 * Lodestone
 * made compasses with this property
 * some minerals are radio active
 * Uraninite
 * some minerals react to acid
 * calcite
 * some have electrical properties
 * quartz vibrates with electricity
 * therefore quartz is made into many things