- Physical Property Cleavage Color Crystal Form Fracture Hardness Luster Magnetism Specific Gravity Streak Taste Mineral P 1 (63.98 KiB) Viewed 12 times
- Physical Property Cleavage Color Crystal Form Fracture Hardness Luster Magnetism Specific Gravity Streak Taste Mineral P 2 (68.73 KiB) Viewed 12 times
- Physical Property Cleavage Color Crystal Form Fracture Hardness Luster Magnetism Specific Gravity Streak Taste Mineral P 3 (50.15 KiB) Viewed 12 times
PHYSICAL PROPERTY Cleavage Color Crystal Form Fracture Hardness Luster Magnetism Specific Gravity Streak Taste Mineral Physical Properties Chart Definition Breakage of a mineral along planes of weakness in the crystal structure Visible light spectrum radiation reflected from a mineral Geometric shape of a crystal or mineral Breakage of a mineral, not along planes of weakness in the crystal structure Resistance to scratching or abrasion Character of the light reflected by a mineral Electromagnetic force generated by an object or electrical field Chemical interaction of hydrochloric acid Reaction to HC and calcium carbonate (CaCO₂) Ratio of the mass of a mineral to the mass of an equal volume of water Color of the mineral when it is powdered Nerve ending reaction in the tongue to different chemicals Testing Method Examine the mineral for areas where the mineral is broken Look for areas where the light reflects from planar surfaces This can be easily confused with a crystal face and is the most difficult properties for students to master Look at the sample and determine its color: white, black, green, clear etc Examine and describe the geometric shape of the mineral-cubic, hexagonal etc. Not commonly seen in most introductory lab samples Examine the mineral for areas where the mineral is broken. Describe the breakage as either irregular or conchoidal (has the appearance of broken glass) Use minerals of known hardness from the Mohs Hardness Kits Scratch the unknown mineral with a known hardness to determine which mineral is harder, Continue doing this with harder or softer minerals from the kit until the hardness is determined Look at the sample to determine if the mineral is metallic in appearance (looks like a chunk of metal) or non metallic (doesn't look like a chunk of metal) Use a magnet to determine if the magnet is attracted to the sample Place one small drop of HCI on a sample a watch for a reaction-effervesces (bubbles) Click here to see an short animation (351 Kb) Generally not determined in an introductory lab Look this information up in your lab manual once the mineral has been identified Grind a small amount of a mineral into a powder on a porcelain streak plate and determine the color of the powder Lick the mineral (not recommended in an introductory lab-you don't know who has handled or licked the sample before you) Other Fluorescence, Radioactivity Properties Definitions simplified or modified bom Bates, RL and JA Jackson (eds.). 1987. Glossary of Geology American Geological Institute, Alexandria, VA, 788 p Requires special equipment such as a UV lamp and geiger counter. These are not commonly tested for in an introductory lab Below is a table listing some of the aspects of the common lab minerals. This table is not a complete listing of all of the physical properties for each mineral It is designed to highlight those physical properties that are unique to that mineral or assist in identification of that mineral Be aware that not all mineral samples will necessarily show these physical properties For example, all plagioclase has cleavage. The sample you examine may or may not show that cleavage. All minerals have a crystal form However, rarely do introductory mineral samples show a good crystal form Some types of minerals rarely show a crystal form and even museum collections may not contain good examples of a mineral's crystal form.
Apatite Augite Biotite Calcite H-3, reacts with HCI, 3 directions of cleavage (thombic cleavage) Corundum H-9, often shows hexagonal crystal form Dolomite Reacts to HCL in its powdered form, similar properties to calcite Fluorite Galena Garnet Mineral Identification - Diagnostic Physical Properties Green color, H-5, may show hexagonal crystal form Dark or dull green color, 2 cleavages at -90 degrees, similar properties to Hornblende Black color, one perfect direction of cleavage resulting in the mineral pealing into thin, flexible sheets, similar properties to Muscovite Graphite Gypsum Halite H-4, 4'directions of cleavage, often purple in color (can be white clear, yellow, green) Gray, metallic mineral, 3 directions of cleavage (cubic): Typically reddish brown color, no cleavage, commonly found in twelve-sided crystals (dodecahedrons) "Pencil lead", soft metallic mineral, gray streak H-2, can be scratched with a fingernail "Salt". H-25, cannot be scratched with a fingernail, 3 directions of cleavage (cubic), salty taste Hematite Reddish brown streak, "rust" Hornblende Black to dk green color, 2 directions of cleavage at 120 or 60 degrees, similar properties to Augite Magnetite Magnetic, metallic mineral Muscovite Clear or translucent color, one perfect direction of cleavage resulting in the mineral pealing into thin, flexible sheets, similar properties to Biotite Olivine Apple green or yellowish green color, H-7 (often difficult to determine), conchoidal fracture, no cleavage Orthoclase H-6, salmon pink color is typical, perthitic intergrowths are common, 2 directions of cleavage at 90 degrees, similar properties to plagioclase Plagioclase H-6, white or gray color, striations may be seen on cleavage surface, 2 directions of cleavage at 90 degrees, similar properties to orthoclase Pyrite Fool's Gold, gold metallic color Quartz H-7, conchoidal fracture, no cleavage, color is typically white or clear but can be pink, red, purple, black Yellow color, rotten egg" smell if burned Sulfur Talc H-1, very soft, easily scratched by fingernail
3. Identify the rock specimens provided and identify each one in the accompanying table. (8) Intrusive/ Texture Extrusive Bin number 2 3 4 5 Other features Major minerals present Name