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oregradepetro.bsky.social
Ore Grade Petrology
@oregradepetro.bsky.social
250 followers 140 following 18 posts
We promote reflected light petrology and ore deposit research through the power of content creation!
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oregradepetro.bsky.social
A reflected light photomicrograph showing coarse-grained molybdenite (Mo; MoS₂) from Moonta, South Australia, Australia. ⚒⛏🧪🔬
October 10, 2023 at 10:37 PM
oregradepetro.bsky.social
A reflected-light photomicrograph showing coarse-grained davidite (Dvd; Ce(Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH,F)38) and fine-grained disseminated pyrite (Py; FeS₂). Location of this sample is unknown. 🔬🧪⛏⚒
A reflected light photomicrograph showing a coarse-grained grey to steel-grey coloured mineral, which is davidite, a Ce bearing REE mineral. Fine-grained square shaped pyrite is disseminated throughout the davidite.
October 9, 2023 at 11:30 PM
oregradepetro.bsky.social
A reflected light photomicrograph showing native gold (Au) from an unknown location. ⚒⛏🧪🔬
A reflected light photomicrograph showing native gold, bright, highly reflective and gold in colour. The gold is irregular in shape and grows between subhedral fine-grained quartz grains, which are a dull grey-brown colour. The image is approximately 1 mm across.
October 8, 2023 at 11:36 PM
oregradepetro.bsky.social
A reflected-light photomicrograph showing coarse-grained enargite (Eng; Cu₃AsS₄) and pyrite (Py; FeS₂). Sample is from Butte, Monata, USA. 🔬🧪⚒⛏
A reflected light photomicrograph showing euhedral, almost rhombic-shaped enargite, a copper arsenic sulphide mineral, which is a medium-grey colour. Enargite is rimmed and overprinted by irregular shaped pyrite, which is a brassy-yellow colour. The image is approximately a mm accross.
October 5, 2023 at 10:10 PM
oregradepetro.bsky.social
A reflected light photomicrograph showing uraninite (Urn; UO₂) overprinted by fine-grained native gold (Au; Au). This sample is from the historic Pallette Mine located in South Alligator River, Northern Territory, Australia. 🧪🔬⚒⛏
A reflected light photomicrograph showing uraninite, which is coarse-grained, circular and a dark dull silver-grey colour overprinted by free gold, which is cold in colour, very fine grained and disseminated throughout the fractures of the uraninite. The width of this image is approximately 1 mm.
October 4, 2023 at 11:24 PM
oregradepetro.bsky.social
A reflected light photomicrograph showing magnetite (Mag; Fe3O4) and chalcopyrite (Ccp; CuFeS₂) from the Ernest Henry Iron-Oxide-Copper-Gold deposit, NW Queensland, Australia. 🧪🔬⚒⛏
An reflected light image down the microscope of the ore mineralogy of the Ernest henry Iron-Oxide-Copper-Gold deposit, located near Cloncurry, Queensland, Australia. Magnetite is a dark silver while chalcopyrite is a gold-yellow colour. These minerals are intertwined and highly irregular in morphology.
October 3, 2023 at 11:01 PM
oregradepetro.bsky.social
A reflected light photomicrograph showing coarse-grained deformed pyrite (Py; FeS₂) from historic gold workings in the Mount Lofty region, South Australia. ⛏⚒🔬🧪
A reflected light photomicrograph a showing yellow-coloured anhedral mineral which is pyrite. The pyrite is fractured in nature by a set of thin veins and cracks running from top to bottom of the image.
October 2, 2023 at 10:48 PM
oregradepetro.bsky.social
A reflected-light photomicrograph showing coarse-grained molybdenite (MoS₂: Mo) from the Moonta Mine, South Australia. 🔬⚒⛏🧪
A reflected light microscope image showing coarse-grained molybdenite (silver-grey) which has sharp boundaries with adjacent clear quartz grains. The molybdenite has changes in its colour associated with birefringence due to its crystal orientation.
October 2, 2023 at 6:30 AM
oregradepetro.bsky.social
Famatinite (Fm; Cu3SbS4) with pyrite (Py; FeS₂), chalcopyrite (Cpy; CuFeS₂), bornite (Bn; Cu₅FeS₄) and covellite (Cov; CuS). Specimen is from an unknown region within Argentina. 🧪⛏⚒🔬

#geology #petrology #mineral #copper #geoscience #petrology #orepetrology #microscopeimages #microscopy
A reflected light photomicrograph showing famatinite (grey) surrounded by minor bornite (brownish bronze) with abundant skeletal chalcopyrite (goldish yellow) and covellite (medium-blue colour). Pyrite (squarish in shape and light yellow in colour) is found throughout the image heterogeneously.
September 15, 2023 at 2:01 AM
oregradepetro.bsky.social
A reflected light photomicrograph showing coarse-grained magnetite (Mag; Fe₂O₃) from Mineville, New York. ⚒⛏🔬🧪
A reflected light photomicrograph showing magnetite, a magnetic iron mineral. Magnetite is a homogenous medium-grey colour. The magnetite has intragrain fractures, which are black and irregular throughout the image. Small black blobs accompany the intragrain fractures.
August 11, 2023 at 7:27 AM
oregradepetro.bsky.social
Reflected light photomicrograph showing davidite (Dvd; (La,Ce,Ca)(Y,U)(Ti,Fe3+)20O38) with minor fine-grained pyrite (Py; FeS₂) from Portugal, East Africa.

View our RL Library Here -https://www.oregradepetrology.com.au/photomicrograph-database-1
A reflected light photomicrograph showing Davidite, a REE-bearing oxide mineral containing Le, and Ce, which is dark-grey in colour with fine grained yellow inclusions of pyrite disseminated throughout. There is small fractures throughout the davidite.
August 10, 2023 at 1:27 AM
oregradepetro.bsky.social
Reflected light photomicrograph showing native gold (Au) mineralisation from an unknown location. ⛏⚒🔬

We are currently making a reflected-light library which is available following this link -

https://www.oregradepetrology.com.au/photomicrograph-database-1
This image shows a reflected light photomicrograph with native gold, which occurs as a right yellow to gold colour located throughout a single vein in the rock. The gold is irregular in form.
August 8, 2023 at 4:45 AM
oregradepetro.bsky.social
A reflected-light photomicrograph showing coarse-grained coronadite (Cor; Pb(Mn4+6Mn3+2)O16) from Bou Tazoult Morocco. ⚒⛏
A reflected-light photomicrograph showing greyish coloured coronadite, a lead manganese oxide mineral with a uneven and irregular microscale texture. There is a small fracture through the middle of the image. The rock in this image was sampled from Bou Tazoult Morocco.
August 4, 2023 at 1:05 AM
oregradepetro.bsky.social
A reflected light photomicrograph showing irregular shaped chalcopyrite (Ccp; CuFeS₂) from the Cobar region, NSW.
A reflected light photomicrograph showing chalcopyrite, a copper sulphide mineral, which is goldish-yellow in colour, and irregular in shape, forming around the multiple basil sections of transparent dolomite, which appears a dark grey to brown colour. The field of view is approximately 2 mm across.
August 3, 2023 at 12:40 AM