Os minerais minérios em microscópio - Guia optico

Os minerais minérios em microscópio - Guia optico

(Parte 3 de 3)

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.01-Copper, Silver and Gold Series

I/A.01-10 Copper Cu 4/m 3– 2/m

I/A.01-15 Allabogdanite (Fe,Ni)2P 2/m 2/m 2/m

I/A.01-20 Silver Ag 4/m 3– 2/m

I/A.01-40 Gold Au 4/m 3– 2/m

I/A.01-50 Auricupride Cu3Au 4/m 3– 2/m

I/A.01-60 Tetraauricupride AuCu 4/m 2/m 2/m

I/A.01-65 Bogdanovite (Au,Te,Pb)3(Cu,Fe) 4/m 3– 2/m

I/A.01-68 Hunchunite (Au,Ag)2Pb 4/m 3– 2/m

I/A.01-70AnyuiiteAu(Pb,Sb)24/m 2/m 2/m

Silver

D E 50 μ50 μ

125 μ47 μ

Descriptions A

Irregular patches of gold (yellow) in pyrite (light cream); West Driefontein, Johannesburg, South Africa [c]; Nic. // Irregular gold grain (yellow) between stibnite (light grey); Murchison Range, South Africa [g]; Nic. // Anhedral electrum (yellowish white), quartz (dark grey); New Bullfrog mine, Nye Co., Nevada, USA [h]; Nic. // Anhedral electrum (yellowish white), argentite (greenish grey), quartz (dark grey); New Bullfrog mine, Nye Co., Nevada, USA [h]; Nic. // Anhedral electrum (yellowish white), pyrite (cream) altered to goethite (bluish grey shades), quartz (dark grey); New Bullfrog mine, Nye Co., Nevada, USA [h]; Nic. //

Gold (Ag-rich Gold = Electrum, Oro)

Geologic Environment:quartz veins, alluvial deposits

Reflection Colour:Internal Reflections: gold-yellow, silver-white (Ag) to copper-red (Cu) blue and green (transmitted light), otherwise opaque Reflectance [%]:

Anisotropy: Pleochroism:

72.26 (92.3 Electrum, 6.6 palladian) isotropic, many scratches suggest otherwise

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.01-Copper, Silver and Gold Series

I/A.01-10 Copper Cu 4/m 3– 2/m

I/A.01-15 Allabogdanite (Fe,Ni)2P 2/m 2/m 2/m

I/A.01-20 Silver Ag 4/m 3– 2/m

I/A.01-40 Gold Au 4/m 3– 2/m

I/A.01-50 Auricupride Cu3Au 4/m 3– 2/m

I/A.01-60 Tetraauricupride AuCu 4/m 2/m 2/m

I/A.01-65 Bogdanovite (Au,Te,Pb)3(Cu,Fe) 4/m 3– 2/m

I/A.01-68 Hunchunite (Au,Ag)2Pb 4/m 3– 2/m

I/A.01-70AnyuiiteAu(Pb,Sb)24/m 2/m 2/m

Gold

D E 20 μ13 μ

125 μ20 μ

Descriptions

Subhedral auricupride (bright orange) in nickeline matrix (slight pinkish brown anisotropy); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. // Subhedral auricupride grain (bright orange) with core of native gold (yellow), nickeline matrix (brownish grey), skutterudite (light grey, lower right corner); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. //

Auricupride

Geologic Environment:low temperature un-mixing of Au-Cu alloys

Reflection Colour:Internal Reflections: violet rose

Reflectance [%]: Anisotropy: Pleochroism: [65]isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.01-Copper, Silver and Gold Series

I/A.01-10 Copper Cu 4/m 3– 2/m

I/A.01-15 Allabogdanite (Fe,Ni)2P 2/m 2/m 2/m

I/A.01-20 Silver Ag 4/m 3– 2/m

I/A.01-40 Gold Au 4/m 3– 2/m

I/A.01-50 Auricupride Cu3Au 4/m 3– 2/m

I/A.01-60 Tetraauricupride AuCu 4/m 2/m 2/m

I/A.01-65 Bogdanovite (Au,Te,Pb)3(Cu,Fe) 4/m 3– 2/m

I/A.01-68 Hunchunite (Au,Ag)2Pb 4/m 3– 2/m

I/A.01-70AnyuiiteAu(Pb,Sb)24/m 2/m 2/m

Auricupride

A 10 μ

3 μ B

Descriptions

Rim of amalgam (medium grey) replacing pyrite (tinted white), goethite (dark grey); Privolnoye deposit, Central Yakutia, Russia [h]; Nic. // Amalgam (dark grey), pyrite (isotropic, brownish grey), goethite (dark grey, some brown internal reflections); Privolnoye deposit, Central Yakutia, Russia [h]; Nic. +

Amalgam (Kongsbergite, Mercury Silver, Silver Amalgam)

Geologic Environment: hydrothermal

Reflection Colour:Internal Reflections: grey

Reflectance [%]: Anisotropy: Pleochroism: [35]isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.02-Mercury and Amalgame series

I/A.02-10 Mercury Hg 3– 2/m

I/A.02-20 Kolymite Cu7Hg6 4– 3 m

I/A.02-2 Belendorffite Cu7Hg6 3 m

I/A.02-28 Eugenite Ag9Hg2 4– 3 m

I/A.02-30 Amalgam Ag2Hg3 4/m 3– 2/m

I/A.02-40LuanheiteAg3Hg6/m 2/m 2/m I/A.02-50 Schachnerite Ag1.1Hg0.9 6/m 2/m 2/m

I/A.02-60 Paraschachnerite Ag3Hg2 2/m 2/m 2/m

I/A.02-70 Goldamalgam (Au,Ag)Hg 4/m 3– 2/m

I/A.02-80 Weishanite (Au,Ag)3Hg2 6/m 2/m 2/m I/A.02-90PotaritePdHg4/m 2/m 2/m

I/A.02-100LeadamalgamHgPb24/m 2/m 2/m

Amalgam

A 5 μ

12 μ B

Descriptions

Anhedral native aluminium (light grey, “grainy” appearance); mud volcano, Caspian Sea near Baku, Azerbaidzhan [h]; Nic. // Native aluminium (fine multicolour reflections); mud volcano, Caspian Sea near Baku, Azerbaidzhan [h]; Nic. +

Aluminium

Geologic Environment:low oxygen fugacity environments; Tolbachik volcano, Kamchatka, Russia

Reflection Colour:Internal Reflections: white

Reflectance [%]: Anisotropy: Pleochroism: [> 70]isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.03-Aluminium-Khatyrkite series

I/A.03-05 Aluminum Al 4/m 3– 2/m

I/A.03-10 Cupalite (Cu,Zn)Al ortho.

I/A.03-20 Khatyrkite (Cu,Zn)Al2 4/m 2/m 2/m

Aluminium

A 60 μ

60 μ B

Descriptions

Rounded grain of native cadmium (white, many scratches); West Verkhoyansky Range, Siberia, Russia [h]; Nic. // Rounded grain of native cadmium (dark brownish grey, many scratches); West Verkhoyansky Range, Siberia, Russia [h]; Nic. +

Cadmium

Geologic Environment:Ust'-Khannin gabbro intrusive

Reflection Colour:Internal Reflections: tin white with bluish tint

Reflectance [%]: Anisotropy: Pleochroism:

[60] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.04-Zinc-Cadmium series I/A.04-10ZincZn6/m 2/m 2/m

I/A.04-15 Brass Cu3Zn2 cub.

I/A.04-20 Zhanghengite (Cu,Zn,Fe,Al,Cr) 4/m 3– 2/m

I/A.04-30 Danbaite CuZn2 cub. I/A.04-40CadmiumCd6/m 2/m 2/m

Cadmium

A 60 μ

60 μ B

Descriptions A

Anhedral native lead (medium grey with brownish tint, translation lamellae; also compare with freshly polished lead in litharge sample - photo A), dolomite (dark grey); Harstigen Mine, Pajsberg, Filipstad, Värmland, Sweden [j]; Nic. // Native lead (isotropic parts and anomalous brownish to bluish grey anisotropy), dolomite (milky internal reflections); Harstigen Mine, Pajsberg, Filipstad, Värmland, Sweden [j]; Nic. + Small grain of native lead (dark with brown internal reflections), dolomite matrix (bright internal reflections); Harstigen Mine, Pajsberg, Filipstad, Värmland, Sweden [j]; Nic. +

Lead (Plumbum)

Geologic Environment:hydrothermal, placers, possibly authigenic processes, replacement of tree roots

Reflection Colour:Internal Reflections:medium grey with brownish tint rare, brownish-red

Reflectance [%]: Anisotropy: Pleochroism: 50.67isotropic, but also anomalous dark to bluish grey anisotropy Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.05-Lead series

I/A.05-10IndiumIn4/m 2/m 2/m

I/A.05-20 Lead Pb 4/m 3– 2/m

I/A.05-30TinSn4/m 2/m 2/m

Lead

B C 250 μ26 μ

Descriptions A

Network of native iron (light grey) in silicate matrix (dark grey); Ovifak, W-Greenland [e]; Nic. // Anhedral iron (light grey) with goethite rim (various darker grey shades), ilmenite (brownish pleochroism), silicates (dark grey); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. // Iron (dark grey), goethite (dark grey), ilmenite (bluish grey anisotropy), silicates (brown and multicolour internal reflections); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. +

Iron (Eisen)

Geologic Environment:meteorites, rarely in basalts which intruded carbon-rich sediments

Reflection Colour:Internal Reflections: white

Reflectance [%]:

Anisotropy: Pleochroism:

58.07 (58.6 nickelian) isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.07-Iron series

I/A.07-10 Iron Fe 4/m 3– 2/m

I/A.07-20 Kamacite alpha-(Fe,Ni) 4/m 3– 2/m

I/A.07-30 Wairauite CoFe 4/m 3– 2/m

Iron

B C 9 μ9 μ

Descriptions

Massive kamacite (medium grey, main mineral) with seams of taenite (medium grey) and unidentified mineral (same grey shade as taenite); Meteorite, locality unknown [d]; Nic. // Kamacite (dark grey, isotropic), taenite (almost black), unidentified mineral (brown internal reflections); Meteorite, locality unknown [d]; Nic. +

Kamacite

Geologic Environment:Fe meteorites

Reflection Colour:Internal Reflections: medium grey with brownish tint

Reflectance [%]: Anisotropy: Pleochroism: [20]isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.07-Iron series

I/A.07-10 Iron Fe 4/m 3– 2/m

I/A.07-20 Kamacite alpha-(Fe,Ni) 4/m 3– 2/m

I/A.07-30 Wairauite CoFe 4/m 3– 2/m

Kamacite

A 40 μ

40 μ B

Descriptions

Anhedral mass and myrmekitic taenite (medium grey) in kamacite (light grey), partial oxidation of taenite to goethite (slightly bluish grey in massive material); Meteorite, locality unknown [d]; Nic. // Taenite (black), kamacite (lighter grey), goethite (brown internal reflections); Meteorite, locality unknown [d]; Nic. +

Taenite (Antitaenite)

Geologic Environment: meteorites

Reflection Colour:Internal Reflections: dark grey

Reflectance [%]: Anisotropy: Pleochroism: [7]isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.08-Nickel series

I/A.08-10 Nickel Ni 4/m 3– 2/m

I/A.08-20 Taenite gamma-(Fe,Ni) 4/m 3– 2/m

I/A.08-30TetrataeniteFeNi4/m 2/m 2/m

I/A.08-40AwaruiteNi2Fe to Ni3Fe4/m 3– 2/m

I/A.08-50JedwabiteFe7(Ta,Nb)36 m m

Taenite

A 60 μ

60 μ B

Descriptions A

Anhedral awaruite (white) and heazlewoodite (slight yellow tint) enclosed by magnetite (medium grey), silicates (dark grey); Oko, NE of Koti, Shikoku, Japan [j]; Nic. // Irregular intergrowth of awaruite (slightly tinted light grey) with goethite (dark grey) and silicates (dark grey); Canyon Creek Trail, Josephine Co., Oregon, USA [j]; Nic. // Awaruite (dark greys, faint anisotropy), goethite (brown internal reflections), silicates (colourless); Canyon Creek Trail, Josephine Co., Oregon, USA [j]; Nic. + Massive awaruite (slightly tinted grey) with inclusions of oregonite (slightly pinkish), silicates and goethite (dark grey); Canyon Creek Trail, Josephine Co., Oregon, USA [j]; Nic. // Anhedral awaruite (white) next to chromite (medium grey) and magnetite (slightly lighter grey), silicates (dark grey); Keeps Mine, Wyangle, Tumut, New South Wales, Australia [j]; Nic. //

Awaruite (Bobrovskite, Josephinite, Souesite)

Geologic Environment:fluviatil placers, serpentinised peridotites, meteorites

Reflection Colour:Internal Reflections: tinted grey

Reflectance [%]: Anisotropy: Pleochroism: 64.98isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.08-Nickel series

I/A.08-10 Nickel Ni 4/m 3– 2/m

I/A.08-20 Taenite gamma-(Fe,Ni) 4/m 3– 2/m

I/A.08-30TetrataeniteFeNi4/m 2/m 2/m

I/A.08-40AwaruiteNi2Fe to Ni3Fe4/m 3– 2/m

I/A.08-50JedwabiteFe7(Ta,Nb)36 m m

Awaruite

D E 125 μ50 μ

125 μ125 μ

Descriptions A

Large patches and lamella of cohenite (slightly more cream than iron) between and in native iron grains (white, almost bluish in comparison), goethite (medium grey, dendritic) as oxidation product; Ovifak, W-Greenland [e]; Nic. // Vermiform cohenite (slightly brighter than iron, cream) in native iron (white); Ovifak, WGreenland [e]; Nic. // Lamellar cohenite (slightly cream) in native iron (white) largely replaced by goethite (large medium grey patches); Ovifak, W-Greenland [e]; Nic. //

Cohenite

Geologic Environment:Fe meteorites, terrestrial Fe from mafic rocks (assimilation of graphite)

Reflection Colour:Internal Reflections: cream-white

Reflectance [%]: Anisotropy: Pleochroism: 57.67 - 59.62slight Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.09-Honquiite-Tantalcarbide series

I/A.09-10 Hongquiite TiO 4/m 3– 2/m

I/A.09-20 Khamrabaevite (Ti,V,Fe)C 4/m 3– 2/m

I/A.09-30TongbaiteCr3C22/m 2/m 2/m

I/A.09-35 Isovite (Cr,Fe)23C6 4/m 3– 2/m

I/A.09-40 Haxonite (Fe,Ni)23C6 4/m 3– 2/m

I/A.09-50 Cohenite (Fe,Ni,Co)3C 2/m 2/m 2/m

I/A.09-5 Niobocarbide (Nb,Ta)C 4/m 3– 2/m

I/A.09-60 Tantalcarbide TaC 4/m 3– 2/m

Cohenite

B C 20 μ125 μ

Descriptions

AIrregular carlsbergite grain (light grey) in kamacite (tinted white); Kenton County Meteorite, Kentucky, USA [h]; Nic. //

Carlsbergite

Geologic Environment:inclusions in kamacite and troilite, Fe meteorites

Reflection Colour:Internal Reflections: light grey with a rose-violet tint

Reflectance [%]: Anisotropy: Pleochroism: 41.00isotropic Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography

I/A.10-Osbornite-Sinoite series

I/A.10-10 Osbornite TiN 4/m 3– 2/m

I/A.10-20 Carlsbergite CrN 4/m 3– 2/m

I/A.10-30 Roaldite (Fe,Ni)4N4 – 3 m

I/A.10-40SiderazotFe5N26 2 2 I/A.10-45 Nierite Si3N4 3 m I/A.10-50SinoiteSi2N2Om m 2

Carlsbergite

A 5 μ

(Parte 3 de 3)

Comentários