Rock and Mineral Identification

Hello Fleming College We have a rock and mineral ID test coming up We got ah 40 rocks and minerals on there 21 minerals and 19 rocks So let's get down to business Start off with our minerals Quartz Quartz has a hardness of 7 and is the hardest mineral in this set The luster is glassy Non-metallic But be careful because quartz can be almost any colour It has concoidal fracture No cleavage but is sometimes in crystal form It has sharp edges and is a common rock forming mineral Calcite Has a hardness of 3 and can be scratched with a knife It's lustre is vitreous to earthy and non metallic It has good cleavage and is rhombic It can be many different colours and effervesces with a dilute ten percent HCL Plagioclase Has a hardness of 6 and a non metallic lustre It streaks white and has good cleavage at right angles And twinning striations It's usually light in colour white or grey Orthoclase A hardness of 6 It's lustre is non metallic vitreous It streaks white it has good cleavage at 90 degrees Colour is most often light to medium red but can be white grey or green Biotite and Muscovite With a hardness of 2.5 to 3 it's very soft It's lustre is non metallic Perfect basal cleavage Splits off easily into thin sheets that are elastic or plastic The colour is opaque to translucent Biotite is always black Muscovite is brown light green or beige Hornblende With a hardness of 5.5 it's as hard as a knife It's lustre is vitreous non metallic It has a bright black splintery appearance It's cleavage not always easy to see Angles fifty six degrees and one hundred twenty four degrees The colour is black to dark green or brown Pyroxene Hardness of 5.5 same hardness as a knife blade The lustre is vitreous to glassy and non metallic The colour is light to medium grey or green has visible cleavage plains at approximately ninety degrees Talc With a hardness of 1 it's very soft and can be scratched with a fingernail The cleavage is perfect basal The streak is white the lustre is pearly to greasy non metallic silky appearance slippery to the touch Colour is pale green white yellow or translucent Pyrite Hardness of 6 to 6.5 it's harder than a knife blade The lustre is metallic it has no cleavage And is massive The streak is greenish or brownish black The colour is opaque pale brass yellow Sometimes called fools gold And is harder than chalcopyrite Chalcopyrite It's hardness is 3.5 to 4 softer than a knife blade It has no cleavage and is massive The lustre is metallic The streak is greenish black Softer than pyrite The colour is brassy to greenish yellow Graphite The hardness of 1 to 2 It's lustre is metallic to dull The cleavage is perfect basal The streak is black and it marks paper Has a greasy appearance and feel The colour is black to steel grey Hematite A hardness of 5.5 to 6.5 The lustre is mostly non metallic Found in compact red earthy masses but can also be metallic dull silver The streak is always red Red powder will come off in your hands The colours are red reddish brown black or metallic steel grey Magnetite With a hardness of 6 it can't be scratched with a knife It's lustre is sub metallic dull metal appearance There is no cleavage and it is massive The streak is black It is magnetic and will affect a compass The colour is iron black Gypsum With a hardness of 2 it scratches easily with a fingernail Lustre is non metallic Clear crystalline form called celonite Compact variety called alabaster most often in massive form Colour usually white also grey reddish or brown Serpentine With a hardness of 2.5 to 4 Cleavage is not prominent concoidal fractures lustre is non metallic greasy to waxy Texture often has greasy or slippery feel And the colour is most often green Barite A hardness or 2.5 to 3.5 The lustre is non metallic vitreous often transparent or translucent The streak is white The cleavage is perfect basal and prismatic or Could be massive with fractures Specific gravity 4.3 to 4.6 Occurs in tabular crystals in granular form or in compact masses resembling marble Colour it's colourless to white yellow brown red green or black Chrysotile Hardness of 2.5 to 4 The texture it has flexible fibres which are easily separated The lustre is non metallic and silky Colours can be green white yellow or brown Galena Hardness of 2.5 Lustre is metallic The specific gravity of 7.6 The streak is medium grey and colours are medium to dark grey The cleavage is parallel to crystal cube faces Pyrrhotite With a hardness of 3.5 to 4.5 The streak is greyish black It has no cleavage and a specific gravity of 4.6 It may be yellow to bronze in colour and tarnishes to iridescent colours and may be magnetic and the lustre is metallic Sphalerite With a hardness of 3.5 to 4 The lustre can be black variety metallic or other common colours that are non metallic It has cleavage with a specific gravity to 3.9 to 4 The streak is brown Colours can be yellow brown red or black if iron is present All right that will do the minerals now let's get into the rocks We're gonna start off with granite It's texture is panoritic medium to coarse grained The structure is massive The colour is white to grey mostly pink The hardness is greater than 5.5 It's composition is made up of quartz orthoclase plagioclase biotite and hornblende Basalt Texture is affinitic fine grained Structure is massive vesicular amygdaloidal flow pillows ropey blocky or columnar The colour is dark grey to black The hardness is greater than 5 to 6 It's composition consists of plagioclase pyroxene olivine and some hornblende and biotite Limestone Texture is calcareous coarse grained The structure is characteristically thick bedded to massive may contain fossils particularly in the cement The colour is variable The hardness is between 3 and 4 Composition it must consist of fifty percent or more of calcite Shale Texture is fine grained Structure is laminated splits into thin plates may contain fossils Colours are light to dark grey iron oxides may give brown and red colours which are dull The hardness is soft easily scratched and weathered may disintegrate in humid climates It's composition consists of silt and clay size particles and clay minerals Gneiss Texture is uneven granular medium to coarse grained crystalline Structure Gneissic banding parallel mineral orientation alternating light and dark bands Colour is light granular layers and dark foliated bands The hardness Granular layers 6 to 7 foliated layers 2.5 to 3 It's composition consists of orthioclase quartz biotite hornblende and it is named for parent rock Marble Texture is even granular fine to medium grained calcite crystals Structure is massive Colour is white but accessory minerals will colour the rock The hardness is 3 is easily scratched and easily eroded It consists of calcite or dolomite Rhyolite Texture is aphanitic may be porphyritic medium to coarse grained Structure is massive Colour is light grey yellow and red The hardness is 6 to 6.5 The composition consists of Quartz sanidine feldspar biotite and hornblende Andesite Texture is aphanitic may be porphyritic fine grained The structure is massive Colour is brown green and dark grey Hardness is 5 to 6 and it's composition consists of plagioclase hornblende pyroxene and biotite Diorite Texture is phaneritic coarse grained structure is massive Colour is light to dark grey Hardness is 5.5 to 6 The composition consists of greater than ten percent of quartz with orthioclase plagioclase hornblende and biotite Gabbro Texture is phaneritic coarse grained The structure is massive The colour is dark grey or greenish black The hardness is greater than 5.5 and the composition consists of plagioclase pyroxene hornblende and olivine Porphyry The texture is porphyritic it has coarse crystals it's a light colour matrix The background is fine grained and dark colour ahh the colour varies The hardness is greater than 5.5 usually picked from the individual mineral the composition varies Nepheline Syenite Texture is phaneritic and coarse grained Structure it has poor cleavage is translucent with greasy to glassy lustre The colours can be white yellow grey green or even reddish or pink The hardness is around 5.5 to 6 The composition consists of sodalite apatite pyroxene sphene and feldspar Limestone Texture calcareous rock fine grained Composed mainly of the mineral calcite The structure stratification usually indistinct sometimes fossils present on surface of rock colour is variable The hardness is ahh 3 to 4 dense variety's break with a concoidal fracture It must consist of fifty percent or more of calcite Dolomite Texture is coarse to fine grained Structure is massive Colour is white colourless buff brown pink or grey Hardness is 3 to 4 effervesces very slowly in cold hydrochloric acid Sandstone Texture even granular sand size Structure is massive bedded cross bedding and ripple marks Colour varies depending on cement white tan brown red or green Hardness varies depending on cementing materials quartz grains The composition consists of quartz grains if feldspar grains called arcos silica carbonates clay or iron oxides as cementing agents Talc Schist Texture is medium to coarse grained talc feel and flakeyness Structure Schistose foliation parallel alignment of flaky minerals make more than fifty percent Colour is silvery white grey yellow to brown tones from iron oxides Hardness and ease of splitting depends on micaceous minerals present usually soft 1 to 3 Composition consists of name for foliation producing minerals which are present micas muscovites chlorite talc and hornblende Slate Texture is dense and fine grained Structure is slatey foliation thinner layers parallel alignment of mica flakes no fossils Colour is usually medium to dark grey or black green purple red brown and shiney lustre The hardness is easily scratched with a knife and is brittle It's parent rocks are shale or mudstone Quartzite Texture is even granular fine to medium grained sugary Structure massive thick bedded outlined of original grains imperceptible Colour is white when pure light to dark grey or brownish to pink from accessory minerals Hardness is 7 tough but brittle with splintery fractures The parent rock is quartz rich sandstones grains and cement Muscovite Schist The texture is medium to coarse grained with a talc like feel and flakeyness The structure is schistose foliation parallel alignment of flaky minerals make up fifty percent The colour is silvery white grey yellow with brown tones from iron oxides Hardness and ease of splitting depend on micaceous minerals present which are soft from 1 to 3 The composition named according to the most conspicuous foliating producing mineral in the rock

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Keywords: Rock, and, Mineral, Identification, ssfcstudybuddy, study, buddy, studios, Fleming, College

Id: 7MvXv66b5h4

Length: 19min 17sec (1157 seconds)

Published: Sun Feb 05 2012

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