Minerals Identification PDF

 Minerals themselves are made up of one or a number of chemical elements with a definite chemical composition. Minerals cannot be broken down into smaller units with different chemical compositions in the way that rocks can.  MINERAL a mineral is a naturally occurring inorganic element or comp...

 Minerals themselves are made up of one or a number of chemical elements with a definite chemical composition. Minerals cannot be broken down into smaller units with different chemical compositions in the way that rocks can.  MINERAL a mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. 1.LUSTER refers to how light is reflected from the surface of a mineral.  2. HARDNESS – it is the ability of mineral to resist scratching. FRIEDRICH MOHS, a German Mineralogist, developed a hardness scale over 100 years ago. Friedrich Mohs,  2. HARDNESS – IT IS THE ABILITY OF MINERAL TO RESIST SCRATCHING. the Mohs scale of hardness measures the scratch resistance of various minerals from a scale of 1 to 10, based on the ability of a harder material/mineral to scratch a softer one. Friedrich Mohs, MINERAL MOHS RELATIVE SCRATCH TEST OTHER FACTS HARDNESS SCALE Talc 1 It flakes easily when scratched by a Softest known fingernail. mineral. Used in talcum powder. Gypsum 2 A fingernail can easily scratch it. Ingredient of plaster Calcite 3 A fingernail cannot scratch it, but a Used in cement copper penny can. Fluorite 4 A steel nail can easily scratch it. Used in toothpaste Apatite 5 A steel nail can scratch it. Mineral in bone Feldspar 6 Cannot be scratched by a steel Ingredient in glass, nail, but it can scratch glass. etc. Quartz 7 Can scratch steel and glass easily. Used in glass Topaz 8 Can scratch quartz. Gemstone Corundum 9 Rubies and Can scratch topaz. Sapphires Diamond 10 Hardest known A diamond can scratch all other mineral. substances. Woman’s best friend 3.CRYSTAL FORM HABIT REFERS TO THE CHARACTERISTIC SHAPE OF A MINERAL UNIT WHICH ARE VISIBLE (EITHER AN INDIVIDUAL CRYSTAL OR A GROUP OF CRYSTAL). 4. COLOR ONE OF THE MOST OBVIOUS CHARACTERISTIC OF A MINERAL, BUT GENERALLY NOT THE MOST USEFUL DIAGNOSTIC FEATURE. MINERALS ARE COLORED BECAUSE CERTAIN WAVE LENGTHS ARE ABSORBED AND THE COLOR RESULTS FROM THE COMBINATION OF THOSE WAVE LENGTHS THAT REACH THE EYE. 5. STREAK IS THE MINERAL’S COLOR IN POWDERED FORM. IT CAN BE USEFUL FOR IDENTIFYING METALLIC AND EARTHY MINERALS. NON-METALLIC MINERALS USUALLY GIVE A WHITE STREAK BECAUSE ARE VERY LIGHT-COLORED. OTHER MINERALS MAY HAVE VERY DISTINCTIVE STREAKS. HEMATITE- FOR EXAMPLE, ALWAYS GIVES A REDDISH- BROWN STREAK NO MATTER WHAT TYPE OF LUSTER IT DISPLAYS. 6. CLEAVAGE IT IS THE ABILITY OF A MINERAL TO BREAK ALONG PREFERRED PLANES. THE NUMBER OF CLEAVAGE PLANES IN A MINERAL MAY ALSO AID ITS IDENTIFICATION. CLEAVAGE TYPICALLY OCCURS IN EITHER ONE, TWO, THREE, FOUR OR SIX DIMENSIONS. THE TENDENCY OF A MINERAL TO BREAK EVENLY ALONG ITS WEAKEST PLANE. FRACTURE - MINERAL BREAKS UNEVENLY OR IRREGULARLY. 7. SPECIFIC GRAVITY IS THE “ HEAVINESS” OF A MINERAL. IT IS DEFINED AS NUMBER THAT EXPRESSES THE RATIO BETWEEN THE WEIGHT OF A MINERAL AND THE WEIGHT OF AN EQUAL VOLUME OF WATER. WATER HAS A SPECIFIC GRAVITY OF “1”.  8. OTHERS MAGNETISM, ODOR, TASTE, TENACITY, REACTION TO ACID, ETC. MAGNETITE IS STRONGLY MAGNETIC; SULFUR HAS DISTINCTIVE SMELL; HALITE IS SALTY; CALCITE FIZZES WITH ACID AS WITH DOLOMITE BUT IN POWDERED FORM; ETC.  TENACITY- toughness of a mineral.it is the way in which a mineral is mechanically deformed 1. FRAGILE- EASILY BROKEN BY CLEAVING EX.SULFUR 2. MALLEABLE- CAN BE FLATTENED INTO SHEETS WITHOUT BREAKING EX.GOLD 3. DUCTILE-CAN BE DRAWN-OUT INTO WIRES WITHOUT BREAKING EX.COPPER 4. SECTILE-CAN BE CUT WITH A BLADE INTO SHAVINGS EX.GYPSUM 5. FLEXIBLE-CAN BE EASILY BENT WITHOUT BREAKING EX.MOLYBDENITE 6. ELASTIC-CAN BE BENT, AND WHEN RELEASED SPRINGS BACK TO ITS ORIGINAL SHAPE EX.MICAS MINERALS CAN BE CLASSIFIED ACCORDING TO THEIR CHEMICAL COMPOSITION.  EXAMPLES: METALS – CHROMIUM NON-METALS – DIAMOND, GRAPHITE METALLOIDS – BRASS, IRON-NICKEL NATIVE ELEMENTS CLASS- made of just a single element, bonded to itself  EXAMPLES: CARBONATES : ARAGONITES (CACO3), CERUSSITE (PB CO3), CALCITE (CA CO3) NITRATES: NITRATINE (NaNO3), NITER (KNO3) BORATES: BORAX (NA2B2O7.10H2O), BORACITE Carbonates Class – minerals composed of carbonates, nitrates and borates  EXAMPLES: OXIDES CLASS- OXIDES:CUPRITE (CU2O), HEMATITE (FE2O3), ICE (H2O} MINERALS HYDROXIDES: MANGANITE [MNO(OH)], GIBBSITE CONTAINING OXIDES AND HYDROXIDES  EXAMPLES: PHOSPHATES: APATITE, CORNETITE, TORBERNITE VANADATES: CARNOTITE, VANADINITE ARSENATES: ADAMITE, ROSELITE, LIROCONITE ANTIMODATES: BINDHEIMITE, CYANOPHYLLITE PHOSPHATE CLASS – MINERALS CONTAINING PHOSPHATES, ARSENATES, VANADATES, ANTIMONATES SILICATES CLASS – minerals composed of silicate tetrahedron (SiO4) SULFATES CLASS: minerals composed of sulfates, sulfides, EXAMPLES: ALUNITE, BARITE, EPSOMITE, chromates, molybdates, selenates, POLY HALITE selenites, tellurates, tellurites and tungstates, SULFIDES CLASS- minerals EXAMPLES: BORNITE, CUBANITE, PYRITE, composed of sulfides, selenides, JORDANITE tellurides, arsenides, antimonides, bismuthides and sulfosalts SOME OF THE COMMON ROCK-FORMING MINERALS ALONG WITH THEIR PHYSICAL AND CHEMICAL PROPERTIES: