Tipe Endapan
Early Magmatic
Pegmatit
Porfiri
Skarn
Epithermal (HS)
Epithermal (LS)
Pengertian
dihasilkan dari proses magmatik langsung, terbentuk dengan cara diseminasi, segregasi, dan injeksi.
hasil kristalisasi magma granitik yang memiliki ukuran kristal sangat besar, pada kondisi larutan dengan kandungan air yang cukup tinggi
terbentuk karena adanya kontak intrusi plutonik intermediet-asam dengan batuan disampingnya.
terbentuk pada kontak intrusi plutonik dengan batuan induk induk karbonat
Dominasimagmatic
Dominasi air meteorik
VHMS
(quartz-alunite, alunitekaolinite, enargite-Au)
Tipe/model endapan :
SEDEX
Merupakan endapan sulfide logam
Endapan ini memiliki host rocks
dasar yang terdapat di sekuen
batuan sedimen, sedimen, umumnya shales
vulkanik submarine. Endapan biji
dan chert.
memiliki kadar sulfide yang sangat
Lowell Gilbert Model dan Diorite
tinggi.
Model
Tipe bijih : Cu-only, Cu-Au, Cu-Mo, Cu-Mo-Au Tekstur
diseminasi, podiform, stratiform.
Fanerik
vein (A, B, C), stockwork, breccia, fracture, porfiritik
pervasive, pervasive, massif massif stratiform, stratiform, vein related
diseminasi, breccia, veins, vuggy quartz
open space filling, balded, comb, colloform,
crustiform,
akumulasi coloform growth zone, banded/layered banded/layered facies antara sulfide
drustiform, pengendapan pengendapan perlapisan perlapisan
cockade, botryoidal.
(bedding,
banding
sulfide
dan mineral hidrotermal lainnya.
laminasi),
diseminasi, stockwork.
Mineral Bijih
kromit, magnetit, ilmenit, pirit, kalkopirit kalkopirit,, pentlandit, pentlandit, pirhotit. pirhotit.
Arsenopirit,
pyrit,
cassiterit,
pirhotit
kalkopirit, emas, tembaga, molybdenite, bornite, magnetit, enargit
emas, tembaga, besi, pirit, pirhotit, pirhotit, magnetite, magnetite, haematite haematite
pirit, enargit, enargit, kalkopirit, tennanite, tennanite, covellit, emas, tellurides,
Arsenopirit, emas, kalkopirit, galena, sphalerit,, elektrum
sulfide (pirit, pirhotit, markasit, arsenopirit, kalkopirit, sfalerit, galena).
pirit, galena, galena, sphalerite sphalerite,, pirhotit
Gambar
Ilmenit mengandung Haematite
Ilmenite dan haematite in Kimberlite pipe
Wolframite dan cassiterite
Chalcopyrite dan rutile di Porphyry Copper
Molybdenite, Chalcopyrite, Quartz.
Sulphide skarn. Pyrite (yellow-white, bottom right) is intergrown with marcasite (white to light pinkwhite, centre bottom), showing strong reflection pleochroism and bireflectance (centre). A lath-shaped marcasite aggregate (top left) is a pseudomorph after pyrrhotite. Chalcopyrite (yellow, top) is intergrown with inclusion-free sphalerite (light grey, centre) and minor pyrargyrite (blue, centre, top left). Dark grey areas are silicate.
Euhedral pyrite within laths of alunite Pentagonal dodecahedron pyrite in auriferous quartz vein.
Subhedral Enargite in vug of silica alteration
Platy sulfide aggregates.
Galena, chalcopyrite, sphalerite, small pyrite
Kalkopirit, sphalerit (Rammelsberg CUZn-Pb SEDEX deposit)
Pyrit, pyrhotit (Rammelsberg CU-ZnPb SEDEX deposit)
Chalcopyrite, bornite, chalcosite, covelline, molybdenite
Tekstur chromite di bijih stratiform dan podiform. a.Fine-grained b. Coarse-grained
Pyrite-enargite-covellite and late covellite in the vug Euhedral - subhedral magnetite (light brown, centre) has thin rims of haematite (white, higher reflectance, centre top) due to incipient martitization. Coarsegrained garnet (light grey, bottom right) is the main phase and is intergrown with other silicates (dark grey, centre right). Black areas are polishing Enargite replace by covellite in the pits. vug
Euhedral marcasite in quartz vein
Pyrit, pyrhotit, magnetit (Rammelsberg CU-Zn-Pb
Tetrahidrite, sphalerit, galena, pyrhotit.
Chromite dan magnetite Intergrowth of enargite and luzonite
Pyrit, chalcopyrite, pyrhotite (Rammenlsberg Cu-Zn_Pb SEDEX deposit
Haematite,Magnetite, Chalcopyrite Enargite-luzonite-chalcopyrite microveinlet in the silica alteration
Chromite, chalcopyrite, rutile di Bushveld deposit Spec of chalcopyrite in the massive tennantite
Sphalerit, chalcopyrite, pyrite (Rammenlsberg Cu-Zn-Pb
Skeletal Magnetite Tennantite-chalcopyrite-telluride assemblage
Pyrit dengan tekstur rim oleh galena, sphalerit (RammenlsbergCu-Zn-Pb
Referensi
Euhedral magnetite (pinkish grey) replaces hematite (light grey blades),
Intergrowth of tennantite, galena, chalcopyrite cementing the early formed pyrite of advanced argilic.
Exolution of Ilmenite (brownish grey) and hematite (light grey)
Pyrite-Tennantite-Emplectite
http://www.atlas-of-ore-
http://www.atlas-of-ore-
W.D. Sinclair.2007. Porphyry
minerals.com/ix_t_2.htm#q
minerals.com/ix_t_3.htm#d
Deposits.Canada: Geological Association of Canada
https://journals.lib.unb.ca/inde x.php/GC/article/viewFile/33
http://www.atlas-of-ore-
26/3843 (J. M. Duke. Ore
minerals.com/ix_t_3.htm#j
Deposit Models 7. Magmatic Segregation Deposits of
http://ore.um.ac.ir/parameters/ore/fil
Chromite . Geoscience
emanager/Porphyry%20copper.pdf
Canada. Volume 10. Number 1)
http://www.mdpi.com/2075163X/6/2/46/htm
http://eprints.utas.edu.au/10703/4/ch .5 _PhD_thesis_(full_version)_June_2 010.pdf
http://www.science.smith.edu/ge Myo Min Tun, I Wayan Warmada,
Noel C. White and Jeffrey W.
osciences/skarn/aboutskarn.html
dkk. 2014. HighSulfidation
https://pubs.usgs.gov/of/1995/of
Epithermal Mineralization and Ore
Deposit: Styles, Characteristic, and
r-95-0831/CHAP12.pdf
Mineral Assemblages of Cijulang
Exploration. SEG Newsletter, No. 23,
Prospect, West Jawa, Indonesia. J.SE
pp.1, 9-13.
Asian Appl. Geol, Vol. 6(1), pp 29-38. http://www.minsocam.org/msa/ OpenAccess_publications/Craig _Vaughan/Craig_Vaughan_Chp Noel C. White and Jeffrey W. tr_10.pdf http://www.atlas-of-oreminerals.com/plate64b.htm
Hadenquist. 1995. Epithermal Gold Deposit: Styles,
Hadenquist. 1995. Epithermal Gold
http://www.atlas-of-oreminerals.com/
https://www.esga.org/fileadmin/sga/Mineral_Deposit _Archive/Rammelsberg/Rammelsberg_ Konka, Solomon Gebreselassie. 2015. SGA_MDA.pdf Samuel Abraham, Bheemalingeswara
Geology of Volcanogenic Massive
Wei Zhai, Xiaoming Sun, et al. 2009. Geology, geochemistry, and genesis of Axi: A Paleozoic low-sulfidation type epithermal gold deposit in Xinjiang, China. China: Elsevier.
Sulfide Deposit near Meli, Northwestern Tigray, Northen Ethiopia. Momona Ethiopian Kournal
of Science, V7(1):85-104.
Characteristic, and Exploration. SEG Newsletter, No. 23, pp.1, 9-
http://www.minsocam.org/msa/Op
13.
enAccess_publications/Craig_Vau ghan/Craig_Vaughan_Chptr_10.pd f
ENDAPAN MINERAL DAN MINERAL BIJIH
https://pubs.usgs.gov/of/1995/ofr95-0831/CHAP29.pdf
PERBANDINGAN MINERAL ENDAPAN EARLY MAGMATIC : kromit, magnetit, ilmenit, pirit, kalkopirit,
Mineral Bijih
pentlandit, pirhotit.
NAMA MINERAL KOMPOSISI REFLECTANCE WARNA
Chromite
Magnetit
Ilmenit
Pyrite
FeCr2O4 Low Dark grey-brownish gray
Fe3O4 Medium Gray, commonly with brownish tint
FeS2 Strong Cream to white
HARDNESS
Hard (5.5) >magnetit, ~llmenite
Hard: >pyrrhotite,
FeTiO3 Low Gray-white with brownish, pink, or violet tint Hard: >magnetite,
Hard: >arsenopyrite, >hematite, ~marcasite
PLEOKROIK
Non
Non
Weak
Isotropic
BIREFLECTANCE ANISOTROPISM Isotropic
INTERNAL REFLECTION
Geological Environment Associated minerals
brown-red brown (Mg-Al-rich samples) Absent in Fe-rich samples (rare, only in thinnest sections) Cumulate mineral in ultramafics, meteorites Hematite, ilmenite, magnetite, millerite, pentlandite, pyrrhotite, sperrylite, ulvospinel, velleriite
Not present except when Mn rich
Accessory mineral in igneous and metamorphic rocks, biogenic product Bravoite, chalcopyrite, cubanite, galena, hematite, ilmenite, marcasite, pentlandite, pyrite, pyrrhotite, rutile, sphalerite, ulvospinel, valleriite, zincite
Chalcopyrite
Pentlandit
Pyrhotite
Yellow-brassy yellow
(Fe,Ni)9S8 Strong Light creamy or yellowish
Fe1-xS Strong Creamy pinkish brown
Medium: >galena,
Medium: > chalcopyrite,
Non
Weak
Non
Medium; >>ccp,=pentlandite, <
Strong Strong Grey shades, light greenish gray, brownish gray Rare: dark brown
Isotropic, Occasionally slightly anisotropic with tints of violet, brown, turqoise -
Weak Weak-distint, grey-blue to yellow green
Isotropic
Accessory of igneous and metamorphic rocks, placers (black sand deposits)
Sedimentary,magmatic,metamorphic, hdrothermal
Occurs with magnetite, hematite, apatite, rutile, pyrite, pyrrhotite, chromite, tantalite
Triple junctions of Ilmenite (grey with brownish tint, strong bireflectance, fine exsolution lamellae of hematite)
CuFeS2
Strong: yellow-gray, greenish gray, grayish blue
-
-
Hydrothermal slfides, dissemination in igneous rocks
Basic and ultrabasic intrusive igneous rock
Igneous and metamorphic rocks
Practically all minerals but especially arsenopyrite, chalcopyrite, galena, magnetite, marcasite, pyrrhotite, sphalerite
Chalcopyrite occurs with pyrite, molybdenite,pyrrhotite,pentlandite, bornite, digenite, magnetite, and many others minerals. It often alters along cracks and grain boundaries to covellite, chalcosite, and malachite. Intergrowths occur with tetrahedrite, cubanite, galena, sphalerite
Pentlandite is the principal ore of nickel. Pyrrhotite, chalcopyrite, pyrite, violarite, millerite, cubanite, chromite, ilmenite, magnetite, sperrylite
Arsemopyrite, brannerite, carrolite, chalcopyrite, cobaltite, cubanite, galena, ilmenite, magnetite, marcasite, millerite, pentlandite, pyrite, stannite
Cataclastic pyrite (white) partially replaced by chalcopyrite (yellow)
Massive chalcopyrite (yellow), magnetite (medium grey, partially as rim around chalcopyrite), carbonate matrix (dark grey)
Pentlandite “flames” (light cream) in pyrrhotite (brownish tinted grey), pyrite crystal (white), chalcopyrite (yellow), quartz (dark grey);
Anhedral pyrrhotite (brownish tint, bireflectance), small chalcopyrite grains (yellow);
Skeletal intergrowth of chalcopyrite (yellow) with sphalerite (medium grey), anglesite (medium grey but darker than sphalerite)
Massive pentlandite (yellowish cream) with alteration products along cracks, pyrrhotite (slightly darker cream), chalcopyrite(yellow);
Gambar
Slightly rounded euhedral chrimite (Medium grey), silicates (dark grey)
Slice of euhedral chromite (brown internal reflections in thinnest past), partially serpentised olivine as matrix (bright-yellow internal reflections)
Euhedral magnetite (brownish grey) with crystallographically oriented hematite replacement (light grey), Bushveld, South Africa
Rim of ilmenite (brownish grey pleochroism) around rutile (lamellar twins, bluish to brownish grey pleochroism,
Pyrrhotite (brownish grey shades) with corrugation lamellae;
Magnetite is replaced by chalcopyrite with bornite
bireflectance) in galena (light grey), silicates Framboidal pyrite (cream), barite crystals (dark grey (greyish);
Colloform pyrite (cream, desiccation cracks), galena (light grey, cleavage breakouts),ilmenite (brownish grey, bireflectance), silicates (dark grey);
Pentlandite (cream) with oriented chalcopyrite exsolution (yellow); Massive chalcopyrite replaces py and is mutually intergrown with sphalerite.
ENDAPAN PEGMATITE Mineral bijih NAMA MINERAL KOMPOSISI REFLECTANCE WARNA
: Arsenopirit, pyrit, cassiterit, pirhotit Arsenopyrite
Cassiterite
Pyrite
Pyrhotite
FeAsS Strong White with faint creamy, yellowish, pinksh tint Hard: >loellingite, >magnetite,
SnO2 Low Brownish gray
FeS2 Strong Cream to white
Fe1-xS Strong Creamy pinkish brown
Hard: >>bismuth, >>bismuthinite, >>molybdenite, >stannite
Hard: >arsenopyrite, >hematite, ~marcasite
Weak, white with bluish tint to faint reddish yellow BIREFLECTANCE ANISOTROPISM Strong, red violet
Weak-non
Non
Medium; >>ccp,=pentlandite, <
Strong-weak Moderate
INTERNAL REFLECTION Geological Environment Associated minerals
Abundant: whitish yellow to yellow-brown
Isotropic, Occasionally slightly anisotropic with tints of violet, brown, turqoise -
HARDNESS
PLEOKROIK
High temperature veins, pegmatites, contact metamorphicrocks Commonly associated with hydrothermal gold, also with vein ores of Sn and W in higjtemperature hydrothermal deposits. It is also associated with Ag and Cu ores, galena, sphalerite, pyrite, chalcopyrite.
Granites, pergmatites, alluvial process
Euhedral arsenopyrite (rhombohedral to skeletal, white) in myrmekitic intergrowths of falkmanite (greenish) and galena (light grey);
Cassiterite (medium grey) replaced by stannite (greenish grey), small specs of chalcopyrite (yellow), quartz (dark grey);
Associated with pyrite, arsenopyrite, molybdenite, wolframite, sphalerite, galena, rutile, hematite, magnetite, bismuth, and pyrrhotite. In placer deposits, cassiteritse is found with other detrital heavy mineral.
Strong: yellow-gray, greenish gray, grayish blue -
Sedimentary, magmatic, metamorphic, hdrothermal Practically all minerals but especially arsenopyrite, chalcopyrite, galena, magnetite, marcasite, pyrrhotite, sphalerite
Igneous and metamorphic rocks
Cataclastic pyrite (white) partially replaced by chalcopyrite (yellow)
Anhedral pyrrhotite (brownish tint, bireflectance), small chalcopyrite grains (yellow);
Arsemopyrite, brannerite, carrolite, chalcopyrite, cobaltite, cubanite, galena, ilmenite, magnetite, marcasite, millerite, pentlandite, pyrite, stannite
Gambar
Framboidal pyrite (cream), barite crystals (greyish);
Arsenopyrite twin (blue and brown anisotropy), pyrrhotite (greenish grey anisotropy),sphalerite (isotropic, brown internal reflections);
Colloform cassiterite (internal reflections with various brown shades, grey anisotropy visible in dark layers);
“Wood tin” (finely laminated, various brown internal reflections, grey anisotropy);
Arsenopyrite with rim of pyrrhotite (yellow) PPL
Arsenopyrite with rim of pyrrhotite (yellow) PPL
Pyrrhotite (brownish grey shades) with corrugation lamellae; Colloform pyrite (cream, desiccation cracks), galena (light grey, cleavage breakouts),ilmenite (brownish grey, bireflectance), silicates (dark grey);
ENDAPAN PORFIRI Mineral bijih NAMA MINERAL KOMPOSISI REFLECTANCE WARNA HARDNESS
: kalkopirit, emas, tembaga, molybdenite, bornite, magnetit, enargit Gold
Copper
Molybdenite
Bornite
Enargit
Au
Cu Strong Deep pink, tarnishes brown Soft: >chalcosite,
MoS2 Medium-stron g White, pinkish tint Soft:
Cu5 FeS4 Medium Pinkish borown=orange, tarnishehes-purple Soft: >covellite, `/
Cu3AsS4 Medium Light pinkish brown or pinkish gray Medium: >bornite, >galena, ~/>luzonite, ~/>tennantite,
Bright golden yellow Soft: >stibnite,
PLEOKROIK BIREFLECTANCE ANISOTROPISM Isotropic Many scratcg=hes suggest otherwise INTERNAL Blue and green (transmitted light), REFLECTION otherwise opaque Geological Environment
Quartz veins, alluvial deposit, mesothermal, epithermal, vein, VMS placer, IOGC, porphyry, intrusion related
Associated minerals
In quartz veins with pyrite, arsenopyrite, galena,sphalerite, stibnite, tellurides, chalcopyrite, pyrrhotite, Ag-bearing minerals, Bi-bearing minerals, scheelite, tourmaline, and carbonates. In massive sulphide deposits with pyrite, chalcopyrite, galena, sphalerite. In placer deposit with detrital heavy minerals.
Weak Isotropic
Weak, not always noticeable Weak to absent
Rare, deep red basic Precambrian magmatites, at border between oxidation and cementation zone, cap rocks of Cu sulfide veins, volcanic and sedimentary rocks Porphyry, secondary, supergene, magmatic Small amounts of native copper occur associated with cuprite, malachite, azurite in the oxidized supergene zones of primary copper deposit. It also pccurs with chalcocite, enargite, bornite, pyrrhotite, iron, magnetite. In basalt-hosted deposit, with chalcocite, bornite, chalcopyrite, pyrite.
Porphyry, skarn, vein, magmatic, pegmatite
igneous intrusions, hydrothermal Cu ore veins, alteration product of Cu minerals
Occurs in veins and dissemination wiyh purite, Cassiterite, ccp, covellite, digenite, enargite, chalcopyrite, bpornite, cassiterite, wolframite, sphalerite, tetrahedrite-tennantite bismuthinite, others sulphides.
moderate- to low-temperature hydrothermal veins, epithermal, vein, VMS, porphyry
Commonly associated with chalcopyrite, pyrite, bornite,tetrahedrite-tennantite,covellite, digenite, galena, sphalerite
Gambar
Irregular patches of gold (yellow) in pyrite (light cream);
Skeletal copper (light pink) with small specs of cuprite (bluish grey);
Anhedral electrum (yellowish white), pyrite (cream) altered to goethite (bluish grey shades), quartz (dark grey);
Anhedral native copper (pink tint) next to domeykite (grey) in jasper;
Deformed molybdenite platelets (bright to medium grey, strong bireflectance, pressure twinning), pyrrhotite (pinkish grey);
Radial molybdenite (strong grey bireflectance), vaesite (tinted medium grey), silicate (dark grey);
Anhedral bornite (pinkish grey; Ag-rich) replacing pyrite (white), covellite (blue);
Anhedral enargite (pinkish grey; bireflectance) intergrown with tennantite (greenish) and pyrite (light yellow);
Anhedral bornite (pinkish grey; Ag-rich) with relict chalcopyrite lamellae (yellow), covellite (blue); Massive enargite (violet to bluish grey pleochroism), pyrite (cream), quartz (dark grey);
Massive bornite (pinkish grey) replacing individual laminae of colloform chalcopyrite (light yellow);
Enargite (lamellar blue to brown anisotropy), pyrite (isotropic), quartz (milky to multicolour internalreflections);
Au occurs as subhedral crystals within a quartz veinlet that cross-cuts massive arsenopyrite.
Prismatic enargite (ena) with pyrite and chalcopyriteinclusions.
ENDAPAN SKARN Mineral bijih
: emas, tembaga, besi, pirit, pirhotit, magnetite, haematite
NAMA MINERAL KOMPOSISI REFLECTANCE WARNA HARDNESS PLEOKROIK BIREFLECTANCE ANISOTROPISM INTERNAL REFLECTION
Haematite Fe2O3 Medium Gray-white with bluish tint Hard: >goethite, >ilmenite, >magnetite, ~/
Geological Environment Associated minerals
Magmatic,hydrothermal,metamorphic, sedimentary Common as exsolution lense or lamellae in ilmenite or magnetite, or as a host to lamellae pf the same. It is also commonly associated with pyrite, chalcopyrite, bornite, rutile, chromite, cassiterite, goethite, sphalerite, and with siderite, limonite, and quartz.
Gambar
Large clusters of euhedral and twinned hematite (medium grey, bireflectance);
Colloform hematite (bright red internal reflections, brownish grey anisotropy), goethite (bluish grey anisotropy, brown internal reflections);
Euhedral hematite (lamellar light and dark brownish grey anisotropy, red internal reflections in matrix);
Deformed hematite platelets (medium grey) in tiemannite (light grey);
ENDAPAN EPITHERMAL (HS) Mineral bijih
: pirit, enargit, kalkopirit, tennanite, covellit, emas, tellurides,
NAMA MINERAL KOMPOSISI REFLECTANCE WARNA HARDNESS PLEOKROIK BIREFLECTANCE ANISOTROPISM INTERNAL REFLECTION
Tennanite (cu, Fe)12As4S13 Medium Grayish white-greeenish gray-white, greenish shade Medium: ~chalcopyrite, >digenite,
Covellite CuS Medium Indigo-ble with violet tint to bluish white Soft:
Isotropic Brownish res, reddish
Strong: 45 derjat orange-reddish brown
Geological Environment
Hydrothermal veins, contact metamorphic
Oxidation zone of sulfide Cu deposit, high temperature hydrothermal, porphyry, IOCG Commonly seen with copper and iron sulphides (pyrite, ccp, chalcocite, digenite, bornite.) and is derived from them by alteration. Occurs also with enargite, sphalerite, native copper, cuprite, hematite, limonite, gothite, linnaeite, luzonitem tetrahedrite-tennanite.
Associated minerals
Gambar
Anhedral tennantite (greenish grey) between euhedral pyrite crystals (light Covellite (blue, strong bireflectance) replacing bornite (brownish relicts) and chalcopyrite (yellow lamellae); yellow) and intergrown with enargite (pinkish grey);
ENDAPAN EPITHERMAL (LS) Mineral bijih
: Arsenopirit, emas, kalkopirit, galena, sphalerit,, electrum
NAMA MINERAL KOMPOSISI REFLECTANCE WARNA HARDNESS
Arsenopyrite FeAsS Strong White with faint creamy, yellowish, pinkish tint Hard: >loeelingite, >magnetite,
Sphalerite (Zn, Fe)S Low Dark gray spmetimes with brown or blue tint Medium: >chalcopyrite,
Weak
Galena PbS Strong White-light gray Soft: >>acanthite-argentite, >proustite-pyrargyrite,
PLEOKROIK BIREFLECTANCE ANISOTROPISM INTERNAL REFLECTION
Strong, blue, green, reddish brown-yellow -
Isotropic -
Isotropic Common: white, yellow, reddish, reddish brown, color varies with composition and Fe contens
Geological Environment
High temperature veins, pegmatites, contact metamorphic rocks Commonly associated with hydrothermal gold, also with vein ores of Sn and W in higj-temperature hydrothermal deposits. It is also associated with Ag and Cu ores, galena, sphalerite, pyrite, chalcopyrite.
Hydrothermal Pb sulfides veins, disseminations in igneous and sedimentary rocks, MVT, VMS, SEDEX Gn is a common mieral, particularly associated with sphalerite, pyrite, ccp, tetrahedrite-tennantite, argentite, lead sulphosalts
Hydrothermal sulfide veins, submarine
Associated minerals
Non
Gn, py, marcasite, ccp, po, arsenopyrite, fluorite, tetrahedrite in all types of sulphides deposits.
Gambar
Euhedral arsenopyrite (rhombohedral to skeletal, white) in myrmekitic intergrowths of falkmanite (greenish) and galena (light grey);
Massive galena (light grey) with deformation lamellae (“Bleischweif”), chalcopyrite (yellow, at center);
Massive sphalerite (medium grey) with chalcopyrite disease
Skeletal sphalerite (grey) in chalcopyrite (yellow); Arsenopyrite twin (blue and brown anisotropy), pyrrhotite (greenish grey anisotropy), sphalerite (isotropic, brown internal reflections);
Skeletal galena (light grey) in tennantite (greenish grey);
Anhedral Sphalerite (bright green internal reflections); Galena (light grey) replacing anglesite (dark grey);
Alternating zones of iron-rich (dark brown) and iron poor (yellow) sph in vein.
ENDAPAN VHMS Mineral bijih NAMA MINERAL KOMPOSISI REFLECTANCE WARNA HARDNESS
PLEOKROIK BIREFLECTANCE ANISOTROPISM
: sulfide (pirit, pirhotit, markasit, arsenopirit, kalkopirit, sfalerit, galena).
Marcasite FeS2 Strong Yellowish white with greenish or pinkish tint Hard: ~pyrite, >po
Pyrite FeS2 Strong Cream to white
Pyrhotite Fe1-xS Strong Creamy pinkish brown
Hard: >arsenopyrite, >hematite, ~marcasite
Medium; >>ccp, =pentlandite, <
Strong: white with brown tint, yellow with green tint
Non
Weak-strong: creamy brown to reddish brown along grain boundaries
Weak
Soft: >>acanthite-argentite, >proustitepyrargyrite,
Strong: yellow-gray, greenish gray, grayish blue
Strong, blue, green, reddish brown-yellow
-
-
High temperature veins, pegmatites, contact Hydrothermal Pb sulfides veins, metamorphic rocks disseminations in igneous and sedimentary rocks, MVT, VMS, SEDEX Commonly associated with hydrothermal Gn is a common mieral, particularly gold, also with vein ores of Sn a nd W in higj- associated with sphalerite, pyrite, ccp, temperature hydrothermal deposits. It is tetrahedrite-tennantite, argentite, lead also associated with Ag and Cu ores, galena, sulphosalts sphalerite, pyrite, chalcopyrite.
INTERNAL REFLECTION
-
Isotropic, Occasionally slightly anisotropic with tints of violet, brown, turqoise -
Geological Environment
Sedimentary, hydrothermal, secondary , SEDEX, MVT, epithermal, vein
Sedimentary,magmatic, metamorphic, hdrothermal
Igneous and metamorphic rocks
Practically all minerals but especially arsenopyrite, chalcopyrite, galena, magnetite, marcasite, pyrrhotite, sphalerite
Arsemopyrite, brannerite, carrolite, chalcopyrite, cobaltite, cubanite, galena, ilmenite, magnetite, marcasite, millerite, pentlandite, pyrite, stannite
Cataclastic pyrite (white) partially replaced by chalcopyrite (yellow)
Anhedral pyrrhotite (brownish tint, bireflectance), small chalcopyrite grains (yellow);
Strong, blue, green-yellow
Associated minerals
Arsenopyrite FeAsS Strong White with faint creamy, yellowish, pinkish tint Hard: >loeelingite, >magnetite,
Galena PbS Strong White-light gray
Sphalerite (Zn, Fe)S Low Dark gray spmetimes with brown or blue tint Medium:>chalcopyrite,
Yellow-brassyyellow
Non
Weak
Isotropic
Isotropic
Weak Weak-distint, grey-blue to yellow green
-
Common: white, yellow, reddish, reddish brown, color varies with composition and Fe contens Hydrothermal sulfide veins, submarine Gn, py, marcasite, ccp, po, arsenopyrite, fluorite, tetrahedrite in all types of sulphides deposits.
Chalcopyrite
CuFeS2
Medium: >galena,
Hydrothermalslfides, dissemination in igneous rocks Chalcopyrite occurs with pyrite, molybdenite,pyrrhotite, pentlandite, bornite, digenite, magnetite, and many others minerals. It often alters along cracks and grain boundaries to covellite, chalcosite, and malachite. Intergrowths occur with tetrahedrite, cubanite, galena, sphalerite
Gambar
Radial marcasite aggregate (white) with thin pyrite coating (cream);
Framboidal pyrite (cream), barite crystals (greyish); Radial marcasite (bluish white and cream pleochroism, bireflectance) partially replaced by pyrite (slightly brighter cream than marcasite);
Euhedral arsenopyrite (rhombohedral to skeletal, white) in myrmekitic intergrowths of falkmanite (greenish) and galena (light grey);
Pyrrhotite (brownish grey shades) with corrugation lamellae; Arsenopyrite twin (blue and brown anisotropy), pyrrhotite (greenish grey anisotropy),sphalerite (isotropic, brown internal reflections);
Massive galena (light grey) with deformation lamellae (“Bleischweif”), chalcopyrite (yellow, at center);
Skeletal galena (light grey) in tennantite (greenish grey);
Massive sphalerite (medium grey) with chalcopyrite disease
Massive chalcopyrite (yellow), magnetite (medium grey, partially as rim around chalcopyrite), carbonate matrix (dark grey)
Skeletal sphalerite (grey) in chalcopyrite(yellow); Skeletal intergrowth of chalcopyrite (yellow) with sphalerite (medium grey), anglesite (medium grey but darker than sphalerite)
Colloform pyrite (cream, desiccation cracks), galena (light grey, cleavage breakouts),ilmenite (brownish grey, bireflectance), silicates (dark grey);
Marcasite (brown to turquoise), pyrite (isotropic, here dark cream), sphalerite (isotropic), carbonate (bright internal reflections);
Galena (light grey) replacing anglesite (dark grey);
Anhedral Sphalerite (bright green internalreflections); Massive chalcopyrite replaces py and is mutually intergrown with sphalerite.
Alternating zones of iron-rich (dark brown) and iron poor (yellow) sph in vein.
Mrc, gn, sph, apy
ENDAPAN SEDEX Mineral bijih
:pirit, galena, sphalerite, pirhotit
NAMA MINERAL KOMPOSISI REFLECTANCE
Pyrite FeS2 Strong
Pyrhotite Fe1-xS Strong
Galena PbS Strong
Sphalerite (Zn, Fe)S Low
WARNA HARDNESS
Cream to white Hard: >arsenopyrite, >hematite, ~marcasite Non
Creamy pinkish brown Medium; >>ccp, =pentlandite, <
White-light gray Soft: >>acanthite-argentite, >proustite-pyrargyrite,
Dark gray spmetimes with brown or blue tint Medium: >chalcopyrite,
Strong: yellow-gray, greenish gray, grayish blue
Isotropic
Isotropic
-
-
Common: white, yellow, reddish, reddish brown, color varies with composition and Fe contens
Sedimentary,magmatic, metamorphic,hdrothermal Practically all minerals but especiallyarsenopyrite, chalcopyrite, galena, magnetite, marcasite, pyrrhotite, sphalerite
Igneous and metamorphic rocks
Hydrothermal Pb sulfides veins, disseminations in igneous and sedimentary rocks, MVT, VMS, SEDEX Gn is a common mieral, particularly associated with sphalerite, pyrite, ccp, tetrahedrite-tennantite, argentite, lead sulphosalts
Hydrothermal sulfide veins, submarine
Cataclastic pyrite (white) partially replaced by chalcopyrite (yellow)
Anhedral pyrrhotite (brownish tint, bireflectance), small chalcopyrite grains (yellow);
PLEOKROIK BIREFLECTANCE ANISOTROPISM
INTERNAL REFLECTION Geological Environment Associated minerals
Isotropic, Occasionally slightly anisotropic with tints of violet, brown, turqoise -
Arsemopyrite, brannerite, carrolite, chalcopyrite, cobaltite, cubanite, galena, ilmenite, magnetite, marcasite, millerite, pentlandite, pyrite, stannite
Gn, py, marcasite, ccp, po, arsenopyrite, fluorite, tetrahedrite in all types of sulphides deposits.
Gambar
Framboidal pyrite (cream), barite crystals(greyish);
Pyrrhotite (brownish grey shades) with corrugation lamellae;
Massive galena (light grey) with deformation lamellae (“Bleischweif”), chalcopyrite (yellow, at center);
Massive sphalerite (medium grey) with chalcopyrite disease
Skeletal sphalerite (grey) in chalcopyrite (yellow); Skeletal galena (light grey) in tennantite (greenish grey);
Colloform pyrite (cream, desiccation cracks), galena (light grey, cleavage breakouts), ilmenite
Anhedral Sphalerite (bright green internal reflections); Galena (light grey) replacing anglesite (dark grey);
(brownish grey, bireflectance), silicates (dark grey);
Alternating zones of iron-rich (dark brown) and iron poor (yellow) sph in vein.
REFERENSI
G. Spry, Paul and Brian L. Gedlinskie. 1987. Tables for Determination of Common Opaque Minerals .Ames, Lowa: The Economic Geology Publishing Company. Marshall, Dan. , C.D. Anglin, and Hamid Mumin.2004. Ore Mineral Atlas. Canada: Brandon University. Pracejus, Bernhard. 2008. The Ore Minerals Under The Microscope: An Optical Guide.Amsterdam:Elsevier