rocks and mineras info

Ulexite formula, properties?

NaCaB₅O₉·8H₂O; Fiber optic effect (TV rock), fibrous, hardness 2.5.

Aragonite formula, properties?

CaCO₃; Orthorhombic, needle-like, hardness 3.5-4; Polymorph of calcite.

Azurite formula, properties?

Cu₃(CO₃)₂(OH)₂; Deep blue, earthy, hardness 3.5-4; Copper ore.

Calcite formula, properties?

CaCO₃; Rhombohedral cleavage (3 directions), hardness 3, double refraction, HCl fizz.

Dolomite formula, properties?

CaMg(CO₃)₂; Saddle-shaped crystals, hardness 3.5-4, slow HCl fizz.

Malachite formula, properties?

Cu₂CO₃(OH)₂; Green banded, botryoidal/massive, hardness 3.5-4; Copper ore.

Copper formula, properties?

Back: Cu; Reddish, malleable, metallic luster, hardness 2.5-3; Conducts electricity.

Diamond formula, properties?

C; Hardness 10, adamantine luster, octahedral; Gem, industrial cutting.

Gold formula, properties?

Back: Au; Yellow metallic, malleable, high SG (19.3), hardness 2.5-3; Jewelry, electronics.

Graphite formula, properties?

Back: C; Greasy feel, hardness 1-2, black streak; Lubricant, pencils; Polymorph of diamond

Silver formula, properties?

Back: Ag; White metallic, tarnishes, hardness 2.5-3; Jewelry, conductors.

Sulfur formula, properties?

Back: S; Yellow, resinous luster, hardness 1.5-2.5, rotten smell; Acids, fertilizers.

Fluorite formula, properties?

Back: CaF₂; Octahedral cleavage, hardness 4, fluorescent; Flux in steel, toothpaste.

Halite formula, properties?

Back: NaCl; Cubic, salty taste, hardness 2.5; Table salt, evaporite.

Quartz formula, properties?

SiO₂; Hexagonal crystals, hardness 7, conchoidal fracture, vitreous luster; Common rock-forming mineral.

Orthoclase formula, properties?

KAlSi₃O₈; Two cleavages at 90^ ext{o}, hardness 6, salmon pink to white; Igneous and metamorphic rocks.

Muscovite formula, properties?

KAl₂(AlSi₃O₁₀)(OH)₂; Perfect basal cleavage (flexible sheets), hardness 2-2.5, pearly luster; Mica group.

Pyrite formula, properties?

FeS₂; Brassy yellow, metallic luster, hardness 6-6.5, often cubic crystals; "Fool's Gold".

Hematite formula, properties?

Fe₂O₃; Red-brown streak (diagnostic), metallic to earthy luster, hardness 5.5-6.5; Major iron ore.

Gypsum formula, properties?

CaSO₄·2H₂O; Hardness 2 (can scratch with a fingernail), often transparent, platy cleavage; Used in plaster and drywall.

Magnesite formula, properties?

MgCO₃; White, cubic cleavage, hardness 3.5-4.5.

Rhodochrosite formula, properties?

MnCO₃; Pink banded, rhombohedral cleavage, hardness 3.5-4.5.

Siderite formula, properties?

FeCO₃; Brown, rhombohedral cleavage, hardness 3.5-4.5.

Corundum formula, properties?

Al₂O₃; Hardness 9, hexagonal, barrel-shaped crystals; Gem varieties: Ruby, Sapphire.

Goethite/Limonite formula, properties?

FeO(OH) / Hydrated Iron Oxide; Brownish-yellow, earthy, hardness 5-5.5; Iron ore.

Magnetite formula, properties?

Fe₃O₄; Black, metallic, strongly magnetic, hardness 5.5-6.5; Iron ore.

Pyrolusite formula, properties?

MnO₂; Black, sooty, often fibrous/dendritic, very soft (hardness 2-2.5); Manganese ore.

Rutile formula, properties?

TiO₂; Reddish-brown to black, adamantine luster, high refractive index, hardness 6-6.5; Titanium ore.

Zincite formula, properties?

(Zn,Mn)O; Deep orange-red, resinous luster, hardness 4; Zinc ore.

Turquoise formula, properties?

CuAl₆(PO₄)₄(OH)₈·4H₂O; Sky blue to green, opaque, hardness 5-6; Gemstone.

Apatite Group formula, properties?

General Ca₅(PO₄)₃(F,Cl,OH); Hexagonal, vitreous luster, hardness 5; Important for phosphorus in fertilizers.

Fluorapatite formula, properties?

Ca₅(PO₄)₃F; Hexagonal, vitreous luster, hardness 5; Main mineral of the Apatite Group, source of fluorine.

Pyromorphite formula, properties?

Pb₅(PO₄)₃Cl; Green, yellow, brown, barrel-shaped crystals, resinous luster, hardness 3.5-4.

Vanadinite formula, properties?

Pb₅(VO₄)₃Cl; Red, orange, brown, hexagonal prisms, resinous luster, hardness 3-4; Vanadium ore.

Barite formula, properties?

BaSO₄; High specific gravity (4.5), tabular crystals, typically white, hardness 2.5-3.5; Used in drilling mud.

Celestite formula, properties?

SrSO₄; Pale blue, tabular or fibrous crystals, hardness 3-3.5; Source of strontium.

Alabaster (Gypsum variety) properties?

Massive variety of Gypsum; Fine-grained, translucent, used for carvings.

Satin Spar (Gypsum variety) properties?

Fibrous variety of Gypsum; Silky luster, often columnar.

Selenite (Gypsum variety) properties?

Crystalline variety of Gypsum; Transparent, often cleavable into sheets, known for "desert rose" formations.

Bornite formula, properties?

Cu₅FeS₄; Iridescent "peacock ore," tarnishes quickly, metallic luster, hardness 3.

Chalcopyrite formula, properties?

CuFeS₂; Brassy yellow, metallic, often tarnishes to iridescent colors, hardness 3.5-4; Major copper ore.

Galena formula, properties?

PbS; Metallic, silver-gray, cubic cleavage, high specific gravity (7.5), hardness 2.5; Major lead ore.

Sphalerite formula, properties?

(Zn,Fe)S; Resinous to metallic luster, yellow, brown to black, strong cleavage, hardness 3.5-4; Major zinc ore.

Stibnite formula, properties?

Sb₂S₃; Metallic, lead-gray, elongated prismatic crystals (often curved), very soft (hardness 2), perfect cleavage; Antimony ore.

Amphibole Group properties?

Complex inosilicate; Prismatic crystals with 120^ ext{o} / 60^ ext{o} cleavage angle; Common rock-forming minerals.

Actinolite formula, properties?

Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂; Green, fibrous to bladed crystals, part of Amphibole Group, hardness 5.5-6.

Hornblende formula, properties?

Complex silicate (Ca,Na)₂-₃(Mg,Fe,Al)₅(Al,Si)₈O₂₂(OH)₂; Dark green to black, prismatic, two cleavages at approximately 124^ ext{o} and 56^ ext{o}, hardness 5-6; Common in igneous and metamorphic rocks.

Feldspar Group formula, properties?

(K,Na,Ca)(Al,Si)₄O₈; Two good cleavages at 90^ ext{o}, hardness 6; Most abundant mineral group in Earth's crust.

Plagioclase Feldspars properties?

(Na,Ca)Al(Si,Al)Si₂O₈; Striations (twinning lamellae) on cleavage surfaces; Solid solution series from Albite to Anorthite.

Albite formula, properties?

NaAlSi₃O₈; White, plagioclase feldspar, 90^ ext{o} cleavage, striations, hardness 6.

Labradorite formula, properties?

(Ca,Na)(Al,Si)AlSi₂O₈; Grey to dark, plagioclase feldspar, often exhibits labradorescence (iridescent play of color), hardness 6.

Potassium Feldspars properties?

KAlSi₃O₈; Two cleavage planes at 90^ ext{o}; Includes Orthoclase, Microcline, and Sanidine.

Amazonite formula, properties?

KAlSi₃O₈; Green to blue-green variety of Microcline (K-feldspar), hardness 6.

Microcline formula, properties?

KAlSi₃O₈; A K-feldspar polymorph of orthoclase, often exhibits grid-twinning, hardness 6.

Garnet Group formula, properties?

A₃B₂(SiO₄)₃ where A=Ca,Mg,Fe,Mn and B=Al,Fe,Cr; Isometric crystals, no cleavage, hardness 6.5-7.5; Used as abrasive and gemstone.

Almandine formula, properties?

Fe₃Al₂(SiO₄)₃; Red to reddish-brown, iron aluminum garnet, hardness 7-7.5; Common garnet.

Grossular formula, properties?

Ca₃Al₂(SiO₄)₃; Green, yellow, orange, white; Calcium aluminum garnet, hardness 6.5-7.5.

Kaolinite formula, properties?

Al₂Si₂O₅(OH)₄; White, earthy, very soft (hardness 1-2), clay mineral; Used in ceramics, paper filler.

Kyanite formula, properties?

Al₂SiO₅; Blue, bladed crystals, anisotropic hardness (4-5 parallel to blades, 6-7 perpendicular); Indicator of high-pressure metamorphism.

Mica Group properties?

Phyllosilicates; Perfect basal cleavage (flaky sheets), pearly luster, flexible.

Biotite formula, properties?

K(Mg,Fe)₃(AlSi₃O₁₀)(OH)₂; Black or dark brown, perfect basal cleavage (elastic sheets), hardness 2.5-3; Iron-magnesium mica.

Lepidolite formula, properties?

K(Li,Al)₃(Al,Si)₄O₁₀(F,OH)₂; Lilac to pink, perfect basal cleavage, lithium-bearing mica, hardness 2.5-3.

Olivine formula, properties?

(Mg,Fe)₂SiO₄; Olive-green, granular, no cleavage, hardness 6.5-7; Common in mafic igneous rocks.

Prehnite formula, properties?

Ca₂Al(AlSi₃O₁₀)(OH)₂; Pale green, botryoidal or globular aggregates, hardness 6-6.5.

Pyroxene Group properties?

Inosilicates; Short, stout prismatic crystals, two cleavages at 87^ ext{o} and 93^ ext{o}; Common rock-forming minerals.

Augite formula, properties?

(Ca,Mg,Fe)Si₂O₆; Dark green to black, stout prisms, 87^ ext{o} cleavage, hardness 5.5-6; Common clinopyroxene.

Rhodonite formula, properties?

(Mn,Fe,Ca)SiO₃; Rose-pink to reddish-brown, often with black manganese oxide veins, hardness 5.5-6.5.

Spodumene formula, properties?

LiAlSi₂O₆; White, green, pink, prismatic crystals, hardness 6.5-7; Lithium ore; Gem varieties: Kunzite (pink), Hiddenite (green).

Aventurine (Quartz variety) properties?

Green, reddish-brown, or yellow-brown quartz with tiny platy inclusions (e.g., fuchsite for green) giving a shimmering effect.

Agate/Chalcedony (Quartz variety) properties?

Microcrystalline varieties of quartz, often banded (agate) or waxy/fibrous (chalcedony), hardness 7.

Amethyst (Quartz variety) properties?

Purple macrocrystalline quartz, color from iron impurities and irradiation.

Citrine (Quartz variety) properties?

Yellow to orange macrocrystalline quartz, often heat-treated amethyst.

Jasper (Quartz variety) properties?

Opaque, microcrystalline quartz, typically red, yellow, brown, or green, often mottled or banded.

Milky Quartz (Quartz variety) properties?

Translucent to opaque white quartz due to fluid inclusions.

Opal properties?

Hydrated amorphous silica (SiO₂·nH₂O); Play of color (precious opal), conchoidal fracture, hardness 5.5-6.5.

Rock Crystal (Quartz variety) properties?

Pure, transparent, colorless quartz.

Rose Quartz (Quartz variety) properties?

Pink macrocrystalline quartz, color often from microscopic inclusions of dumortierite or titanium.

Smoky Quartz (Quartz variety) properties?

Brown to black macrocrystalline quartz, color from natural radiation.

Tiger's Eye (Quartz variety) properties?

Chatoyant (silky luster) variety of macrocrystalline quartz, typically golden to red-brown, formed from altered crocidolite.

Sodalite formula, properties?

Na₈(Al₆Si₆O₂₄)Cl₂; Blue, massive, dodecahedral, hardness 5.5-6; Gemstone, ornamental stone.

Staurolite formula, properties?

(Fe,Mg)₂Al₉(Si,Al)₄O₂₂(OH)₂; Brown, prismatic crystals, often twinned in 90^ ext{o} cross shapes, hardness 7-7.5.

Stilbite formula, properties?

NaCa₂Al₅Si₁₃O₃₆·17H₂O; White, pink, salmon, often "sheaf-of-wheat" aggregates, zeolite mineral, hardness 3.5-4.

Talc formula, properties?

Mg₃Si₄O₁₀(OH)₂; Very soft (hardness 1), greasy feel, pearly luster, flexible sheets; Used in cosmetics, carving.

Topaz formula, properties?

Al₂SiO₄(F,OH)₂; Commonly yellow, blue, pink, colorless, prismatic crystals, perfect basal cleavage, hardness 8; Gemstone.

Tourmaline formula, properties?

Complex borosilicate; Many colors, prismatic crystals with vertical striations, often triangular cross-section, hardness 7-7.5; Gemstone.

Willemite formula, properties?

Zn₂SiO₄; Green, yellowish, reddish-brown, often fluoresces green, hardness 5.5; Zinc ore.

Wollastonite formula, properties?

CaSiO₃; White, fibrous or bladed, often columnar, hardness 4.5-5; Industrial mineral, used in ceramics.

Zircon formula, properties?

ZrSiO₄; Brown, reddish-brown, grey, tetragonal crystals, adamantine luster, hardness 7.5; Gemstone, radioactive dating.