GUIA DE IDENTIFICACIÓN DE MINERALES Lustre: metálico / submetálico / no metálico Lustre Metálico Generalmente con raya de color, opacos RAYA DUREZA COLOR REMARKS NOMBRE S.G. 2.0 Steel GRAPHITE Black 1 Basal cleavage; Soft, marks on paper, greasy feel. gray GRAFITO Used in lubricants and pencils. S.G. 4.8 PYROLUSITE Iron-black 1-2 Black Radiating fibers, granular masses, or dendritic; sooty. PYROLUSITA An ore of manganese. S.G. 3.3 to 4.0 Yellow Your basic rust. Many forms and lusters. Occurs as Yellow LIMONITE 1 to 5 brown to flattened crystals, massive, reniform, or stalactitic. brown LIMONITA black Common secondary mineral in rocks and soils. An ore of iron. S.G. 4.8 to 5.3 Many forms and lusters (can also occur in sub- Red metallic to non-metallic forms). Can be massive, Steel HEMATITE brown to 1 to 6.5 radiating, botryoidal, and micaceous. The crystalline gray HEMATITA Indian red (metallic and sub-metallic) varieties are generally harder than the earthy (non-metallic) varieties. An ore of iron. S.G. 7.6 Perfect cubic cleavage (3 @ 90°); Occurs in cubes; Gray 2.5 Gray GALENA may be massive or granular; heavy. The most common ore of lead. S.G. 10 to 12 Silvery Hackly fracture, easily distinguished from galena by Light gray white, SILVER 2.5 lack of cleavage. Malleable and ductile. Used in to silver tarnishes PLATA coinage, fillings for teeth, jewelry, silverplate, to black photography, wires. S.G. 19.3 Pale to Hackly fracture. Malleable and ductile. Used in GOLD Yellow 2.5 to 3.0 golden coinage, fillings for teeth, jewelry, goldplate. ORO yellow Extensive use in computer industry as non-corrosive contact points for silicon chips. Bronze, S.G. 4.9 to 5.4 tarnishes Commonly called "peacock ore" because of the Gray to BOURNITE 3.0 to dark purple shine when it tarnishes. black BOURNITA blue and A common source of copper. purple S.G. 8.5 to 9.0 Copper Copper Malleable and ductile. Used in coins, pipes, wires, KOPER 3.0 red red gutters, cooking utensils, pots and pans, jewelry, COBRE decorative items. Greenish- 4 Brass S.G. 4.3 CHALCOPYRITE black yellow The distinctive buttery yellow color is often tarnished CALCOPIRITA purple or gray; yellower and softer than pyrite. An ore of copper. S.G. 4.6 Distinctive chocolate brown streak. Commonly occurs Black to as stratabound deposits in dunite segregations in CHROMITE Chocolate 5.5 dark ultramafic rocks, and as podiform masses in brown brown serpentinite. Used in stainless steel, high CROMITA temperature alloys, and as refractory bricks. The ore of chromium. S.G. 5.2 Conchoidal fracture. Strongly magnetic. Often called MAGNETITE Black 6 Black "lodestone." Common accessory mineral occurring as MAGNETITA disseminated grains in mafic igneous rocks. An ore of iron. S.G. 5.0 Often in cubic crystals. Can be massive, granular. Black to Pale PYRITE 6 Common name: "Fool's gold." Commonly alters to greenish brass PIRITA limonite. Sometimes mined as a source of sulfur. LUSTRE: Sub metálico RAYA DUREZA COLOR REMARKS NOMBRE S.G. 3.3 to 4.0. Your basic rust. Many forms and lusters. Occurs as Yellow- Yellow to LIMONITE 1 to 5.5 flattened crystals, massive, reniform, or stalactitic. brown dark brown LIMONITA Common secondary mineral in rocks and soils. An ore of iron. S.G. 4.8 to 5.3 Many forms and lusters (can also occur in sub-metallic Red to non-metallic forms). Can be massive, radiating, brown to Red, HEMATITE 1 to 6.5 botryoidal, and micaceous. The crystalline (metallic Indian HEMATITA vermillion and sub-metallic) varieties are generally harder than red the earthy (non-metallic) varieties. An ore of iron. LUSTRE: No-metálico. Raya incolora o de color muy claro Dureza: < 2.5 / 2.5 a 3.5 / 3.5 a 5.5 / >5.5 Dureza: < 2.5 (se marca con la uña del pulgar) PATRON D SP. DUREZA COLOR REMARKS NOMBRE RUPTURA GR. Easily scratched with fingernail. Flexible but not elastic; foliated; slick or soapy feeling. Typical luster: Good White, pearly to waxy. Used on baby's butts, TALC 1 cleavage in green, 2.7 and in paints, ceramics, rubber, TALCO 1 direction pink insecticides, and paper. Variety SOAPSTONE can be carved into ornamental shapes and items. Earthy; clayey odor. Earthy to dull luster. A swelling clay, used to stop MONTMOR- White, leaks in soils, rocks, dams, and 1-2 Fracture 2-3 ILLONITE tan, gray basement walls. Due to its excellent MONTMORILONITA water-retention properties, it is also used as a soil additive and kitty litter. Not truly a mineral (lacks fixed Yellow chemical composition). Earthy to Uneven BAUXITE 1-3 brown to 2-3 pisolitic (large round grains). Earthy, fracture BAUXITA red dull to waxy lusters. The most important ore of aluminum. Your basic rust. Many forms and Yellow, lusters. Occurs as flattened crystals, Conchoidal 2.7- LIMONITE 1-5.5 brown to massive, reniform, or stalactitic. fracture 4.3 LIMONITA black Common secondary mineral in rocks and soils. An ore of iron. Many forms and lusters (can also occur in metallic forms). Can be massive, radiating, botryoidal, and Brown, 4.8 Irregular micaceous. The crystalline (metallic HEMATITE 1-6 red, steel to fracture and sub-metallic) varieties are HEMATITA gray 5.3 generally harder than the earthy (non-metallic) varieties. An ore of iron. Characteristic bright yellow color; when small pieces are held in the hand close to the ear, crackling can Conchoidal be heard due to rapid, uneven SULFUR 1.5-2.5 to uneven Yellow 2.1 thermal expansion. Pearly, waxy, AZUFRE fracture resinous, to dull lusters. Used to make sulfuric acid, fertilizers, insecticides, explosives (kaBoom), and medicines. 2 No White, 2.6 Earthy; clayey odor; absorbs KAOLINITE macroscopic often moisture so rapidly that it will stick to KAOLINITA cleavage colored by the tongue. Earthy to dull lusters. impurities Used in refractories, china, pottery and as a filler in paper. Also used in soft-serve ice cream to retard melting on hot summer days. As crystals and broad cleavage flakes with waxy to pearly to vitreous Colorless, lusters (selenite variety); as compact white, fine-grained masses showing no 1 direction, gray, visible cleavage, earthy to dull to perfect, 2 GYPSUM 2 gray- 2.3 waxy lusters (alabaster variety); as directions, YESO brown, fibers with satiny luster (satin spar good pink variety). Large crystals somewhat reddish flexible, but not elastic. Used to make Plaster of Paris and sheetrock wallboard (drywall). Thin sheets are flexible, but not elastic. Lusters typically resinous, waxy, vitreous or dull. A common Dark alteration mineral found in mafic CHLORITE green to 2-2.5 1 direction 2.7 igneous rocks (alteration of the green- ferromagnesian minerals to chlorite black CLORITA results in the greenish tint common to altered basalt, and the re-naming of the rock "greenstone." Platy or fibrous; waxy luster when Wavy, massive, satiny luster when fibrous Green SERPENTINE 2-3 uneven 2.5 (asbestos variety). Used as an and white SERPENTINITA fracture insulating material against heat and electricity. In granular cleavable masses or cubic crystals. Soluble in water; salty White taste. Typical lusters: vitreous, waxy, 3 directions, when 2.1 dull. Common salt: used as a source HALITE 2.5 perfect, pure; may to of sodium compounds and HALITA cubic be red, 2.3 hydrochloric acid; used to salt blue, pink highways in winter; used as a seasoning and preservative in food. Common silicate mineral in felsic igneous rocks and low to medium grade metamorphic rocks. In foliated masses and scales. Transparent, flexible and elastic sheets. Vitreous Pale to pearly luster. Used as insulating 1 direction brown, material in electrical appliances and MUSCOVITE MICA 2.5 2.8 perfect green, as a fireproofing material. Also, MUSCOVITA yellow Muscovite was used as windows before the invention of plate glass, was common as the rear window in early model convertible cars, and is still used as the front view-screen in many "fire-view" type wood stoves. Common ferromagnesian silicate mineral in felsic to intermediate Dark igneous rocks and low to medium BIOTITE 1 direction, brown, grade metamorphic rocks. In MICA 2.5 to 3.0 3.0 perfect green to irregular foliated masses and scales. black Translucent, somewhat flexible and BIOTITA elastic sheets. Pearly to vitreous luster. Forms hexagonal crystals. LUSTRE: No-metálico Raya Incolora o de Color Claro Dureza: 2.5 a 3.5 (no se puede marcar con uña ni con moneda de cobre) PATRON D SP. DUREZA COLOR REMARKS NOMBRE RUPTURA GR. Your basic rust. Many forms and lusters. Yellow, Occurs as flattened crystals, massive, Conchoidal 2.7- LIMONITE 1-5.5 brown to reniform, or stalactitic. Common fracture 4.3 LIMONITA black secondary mineral in rocks and soils. An ore of iron. Many forms and lusters (can also occur in metallic forms). Can be massive, 4.8 radiating, botryoidal, and micaceous. The Irregular Brown, red, HEMATITE 1-6 to crystalline (metallic and sub-metallic) fracture steel gray HEMATITA 5.3 varieties are generally harder than the earthy (non-metallic) varieties. An ore of iron. Platy or fibrous; waxy luster when Wavy, Green and massive, satiny luster when fibrous SERPENTINE 2-3 uneven 2.5 white (asbestos variety). Used as an insulating SERPENTINITA fracture material against heat and electricity. In granular cleavable masses or cubic crystals. Soluble in water; salty taste. White Typical lusters: vitreous, waxy, dull. 3 directions, when pure; 2.1 Common salt: used as a source of HALITE 2.5 perfect, may be to sodium compounds and hydrochloric HALITA cubic red, blue, 2.3 acid; used to salt highways in winter; pink used as a seasoning and preservative in food.