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Texture (grain size, shape, sorting): Mostly sand (1/16 - 2mm grains). Composition (detrital, biochemical, chemical): Detrital sediment grains; derived from the mechanical and chemical weathering of continental rocks, which are comprised mostly of…

Common Forms/Occurrences: Found near hot springs and volcanic regions Useful Identification Test: Identifiable odour when mixed with water (resembles rotton eggs) Chemical formula: S Crystal System: Transparent to translucent crystals or earthy…

Mineralogical Composition: Visible sparkling crystals of platy minerals, bladed crystals, or prismatic crystals; breaks along scaly foliated surfaces Texture (grain size, shape, sorting): Medium to coarse grained; Folitated Metamorphic grade:…

2 male bears wrestle, snow on ground, open water in background

Common Forms/Occurrences: In veins associated with other sulfide minerals Useful Identification Test: Decomposed by H2SO4 and by dilute HNO3 Chemical formula: PbS Crystal System: Forms cubes and octahedrons Colour: Silvery gray Streak: Gray to dark…

Texture (grain size, shape, sorting): Black, layered, brittle rock Composition (detrital, biochemical, chemical): Biochemical sediment grains; plant fragments and/or charcoal Other distinctive properties: May be sooty or bright Common depositional…

Male swims near rocks, others on rocks

Mineralogical Composition: Felsic, Intermediat, and Mafic; Muscovite, Quartz, Potassium Feldspar, Plagioclase Feldspar, Amphibole, Biotite; Olivine, Pyroxene Texture (extrusive/intrusive): Extrusive; Glassy Other distinctive properties: Dark green…

Small group on shore

Key Characteristics: Strong coloration and pleochroism, 2 intersecting cleavages, and diamond shaped basal sections are diagnostic 2V: 2Vx = 35 - 130° Relief: Moderate to high positive relief Cleavage: Two cleavages intersect at 56 ° and 124 °.…

Group huddled on gravel beach, water in background

Common Forms/Occurrences: Found in hydrothermal deposits Useful Identification Test: Insoluble in HCl; When powdered soluble in strong HNO3 Chemical formula: FeS2 Crystal System: Cubes and octahedrons Colour: Brass yellow Streak: Dark gray Lustre:…

Mineralogical Composition: Black glossy rock that breaks along uneven or conchoidal fractures Texture (grain size, shape, sorting): Fine grained; Nonfoliated Metamorphic grade: High Precursor rock: Peat, Lignite, Bituminous coal Commercial…

Common Forms/Occurrences: Secondary mineral formed by alteration of magnesium silicates (ie. Olivine and pyroxene) Useful Identification Test: Very soft to the touch, soapy feel Chemical formula: Mg3Si4O10(OH)2 Crystal System: Cryptocrystalline…

Mineralogical Composition: Visible crystals of two or more minerals in alternating light and dark foliated layers Texture (grain size, shape, sorting): Medium to coarse grained; Folitated Metamorphic grade: Intermediate Precursor rock: Mudstone,…

Texture (grain size, shape, sorting): No visible grains; dark, very fine-grained rock, usually breaks with a conchoidal fracture Composition (detrital, biochemical, chemical): Biochemical sediment grains; shells and shell/coral fragments, and/or…

Common Forms/Occurrences: Found in alabaster, satin spar, and selenite Useful Identification Test: Soft; Shows better cleavage than talc Chemical formula: CaSO4 ? 2H20 Crystal System: Tabular crystals, prisms, blades, or needles Colour: Colourless,…

Texture (grain size, shape, sorting): Rounded gravel, poorly sorted grains larger than 2mm Composition (detrital, biochemical, chemical): Detrital sediment grains; Rock fragments and/or quartz grains and/or feldspar grains and/or clay minerals Other…

Small rocky island with waves

Head of sea lion swimming

Common Forms/Occurrences: Common constituent of Precambrian iron-formations Useful Identification Test: Attracted to a magnet and can be magnetized Chemical formula: Fe3O4 Crystal System: Octahedrons Colour: Silvery gray to black Streak: Dark gray…

Key Characteristics: Relief which changes upon rotation of stage, extreme δ, rhombohedral cleavage and lamellar twinning are all diagnostic. Dolomite usually has higher refractive indices than calcite and may be colorless or iron stained where…

Group huddled together near water on gravel beach

Key Characteristics: Strong brown coloration and plechroism, birds eye and parallel extinction, and high birefringence are diagnostic 2V: 2Vx = 0 - 25° Relief: moderately high positive relief Cleavage: One perfect cleavage Colour and Plechroism:…

Common Forms/Occurrences: Associated with galena and in hydrothermal veins in igneous rocks and contact metamorphic deposits Useful Identification Test: Soluble in HCl with evolution of H2S Chemical formula: ZnS Crystal System: Misshapen…