Characteristics & Properties

What is a Mineral? Must meet 5 characteristics One of these is an mineral and the other is not…

Naturally Occurring The growing process must occur in the natural world Heating/cooling processes in magma

Inorganic Cannot form from materials that were once part of a living thing Coal Obsidian

Solid Definite volume & shape The particles must be pressed tightly together

Crystal Structure The particles must line up in a pattern= that forms a crystal Flat sides are faces Faces meet at edges and corners b3.pdf

Definite Chemical Compound This means that a mineral always contains certain elements in definite proportions Almost all minerals are compounds Their properties will be different from the Some elements can be a mineral

NONaturally Occurring Illegal Inorganic ScienceSolid 'CauseCrystal ScienceStructure Can - Definitely Definite CauseChemical Catastrophes Compound

Identifying Minerals GoldPyriteChalcopyrite

Color Physical property Can only be used to ID a few minerals Many minerals have the same color

Streak Color of the powder form of the mineral Not always the same as the physical color of the mineral

Luster of Minerals MetallicGlassyWaxy, Greasy, Pearly Submetallic/DullSilkyEarthy Luster how light reflects from the faces of the crystal

Heft/Density Mass in a given space (mass/volume) Heft- picking up and feeling – has to be done with minerals of similar sizes Find density using displacement

Hardness Moh’s Hardness Scale A mineral can scratch any mineral softer than itself

Crystal Structure Geologists classify the crystal structures into 6 groups Structure is obvious when grown with plenty of space Crystals grown in tight spaces are often incomplete Some only visible under microscope Opal is the exception to the rule- no crystal structure

Crystal Structures

Cleavage & Fracture Cleavage: splits easily along flat surfaces Depends on arrangement of atoms Fracture How a mineral looks when it breaks apart in a irregular way

Special Properties Fluorescence Electrical Properties Optical Properties Reactivity Magnetism Calcite Aragonite Magnetite