Cole Graham

Scan of a roughly 4cm by 2cm thin section of opaque, black coloured arsenide minerals on the right side and tan/colourless carbonate minerals on the left side. Some of the carbonate minerals show a cross-hatch pattern toward the far left.

False colour gradient map of qualitative Fe content in a roughly 4cm by 2cm thin section of arsenide and carbonate minerals. The left side is carbonate minerals that are rich in Fe, showing a gradient of increasing Fe (warmer colours) towards the left. The right side is partly black (no Fe content) with bands of brighter blue to green representing thin bands of Fe-rich minerals.

Back on my grind of weird Thin Section Thursday posts; here is a thin section scan and corresponding qualitative map of Fe content (via EPMA) with a false colour gradient applied.

This is a vein of Ni-arsenide minerals (opaque, right) and carbonates (colourless, left) #thinsectionthursday #geology

27.11.2025 20:04 — 👍 1    🔁 0    💬 0    📌 0

Halos of smaller grains around native silver are dark brown argentopentlandite and light grey gersdorffite. At top left the smaller native silver is associated with brown argentopentlandite and bright pink breithauptite.

Locality: Easter-Duffy, Great Slave Lake, NWT, Canada

#geology #minerals

17.04.2025 13:40 — 👍 0    🔁 0    💬 0    📌 0

Reflected light microscope image of Cross-shaped white native silver associated with ullmannite (dull grey) and tučekite (grey-brown) with a thin rim of pinkish grey maucherite, all then overgrown by pink nickeline. Halos of smaller grains around native silver are dark brown argentopentlandite and light grey gersdorffite. At top left the smaller native silver is associated with brown argentopentlandite and bright pink breithauptite. Scale bar at the bottom indicates distance equal to 100 microns.

There are never enough reflected light images for #thinsectionthursday so here is my contribution to help fix that!

Cross-shaped white native silver associated with ullmannite (dull grey) and tučekite (grey-brown) with a thin rim of pinkish grey maucherite, all then overgrown by pink nickeline.

17.04.2025 13:40 — 👍 15    🔁 3    💬 1    📌 0

Yep! Given the word limits on bluesky and in the interest of keeping things approachable and understandable to all, I more meant "hexagonal" in the literal, more geometric sense than crystallographic. Lots of compromises to make to keep things concise and in one post. And thanks!!!

22.01.2025 01:42 — 👍 1    🔁 0    💬 0    📌 0

Small rock sample of copper-coloured native Copper with a partially oxidized, green surface. The sample is a perfect hexagonal-prism shaped crystal.

Small rock sample of copper-coloured native Copper with a partially oxidized, green surface. The sample is a perfect hexagonal-prism shaped crystal.

Small rock sample of copper-coloured native Copper with a partially oxidized, green surface. The sample is a perfect hexagonal-prism shaped crystal.

Perfectly hexagonal psuedomorph of Native Copper after aragonite, preserving original crystal shape, with a partially green, oxidized surface.

Locality: Corocoro, Pacajes Province, Pa Paz Department, Bolivia

#mineral #mineralogy #geology

21.01.2025 18:01 — 👍 5    🔁 0    💬 1    📌 0

Small rock sample with a cut and polished face. Contains fine, black, striated crystals of Pirquitasite (left side of sample) in a brown matrix (potentially sphalerite) associated with colloform-esque banding of a black mineral (potentially cassiterite)

Black, striated crystals of Pirquitasite (Ag, Zn, Sn sulfide; left side of sample) in a brown matrix (sphalerite?) associated with colloform banding of a black mineral (cassiterite?)

Locality: Oploca Vein, Pirquitas Mine, Rinconada Department, Jujuy, Argentina

*Pirquitasite Type Locality

#mineral

17.01.2025 04:35 — 👍 4    🔁 0    💬 0    📌 0

Locality: Kipawa alkaline Complex, Sheffield Lake, Les Lacs-du-Témiscamingue, Témiscamingue RCM, Abitibi-Témiscamingue, Québec, Canada

(Gittinsite Type Locality)

#mineral #mineralogy #geology

17.01.2025 04:06 — 👍 0    🔁 0    💬 0    📌 0

Small rock sample with black, glossy Potassic-magnesio-fluoro-Arfvedsonite (sodium amphibole) in light pink Eudialyte matrix, associated with minor honey-yellow grains of Vlasovite, deep purple Fluorite, and white, chalky Gittinsite associatied with the Vlasovite. There are blue tape arrows on the rock, the lower arrow pointing at the arfvedsonite, the upper arrow pointing at a grain of vlasovite.

Small rock sample with black, glossy Potassic-magnesio-fluoro-Arfvedsonite (sodium amphibole) in light pink Eudialyte matrix, associated with minor honey-yellow grains of Vlasovite, deep purple Fluorite, and white, chalky Gittinsite associatied with the Vlasovite. There are blue tape arrows on the rock, the lower arrow pointing at the arfvedsonite, the upper arrow pointing at a grain of vlasovite.

Black, glossy Potassic-magnesio-fluoro-Arfvedsonite (sodium amphibole) in light pink Eudialyte matrix, associated with minor honey-yellow grains of Vlasovite, deep purple Fluorite, and potentially white, chalky Gittinsite associatied with the Vlasovite.

17.01.2025 04:06 — 👍 4    🔁 0    💬 1    📌 0

Small rock sample with a thin vein of bright silver crystals of Gustavite cutting through white carbonate matrix. There is also minor tarnished, grey Arsenopyrite. There is a blue arrow made of tape pointing towards the Gustavite vein.

Small rock sample with a thin vein of bright silver crystals of Gustavite cutting through white carbonate matrix. There is also minor tarnished, grey Arsenopyrite. There is a blue arrow made of tape pointing towards the Gustavite vein.

Thin vein of elongated, striated, bright silver crystals of Gustavite (silver, lead, bismuth sulfide) cutting through white carbonate matrix. There is also minor tarnished, grey Arsenopyrite.

Locality: Arsenic Mine, Lower Rotgülden Lake, Lungau, Salzburg, Austria

#mineral #mineralogy #geology

13.01.2025 04:56 — 👍 3    🔁 0    💬 0    📌 0

Small rock sample with sprays of elongated, very lustrous, metallic, silvery-grey Tintinaite crystals cutting through white Quartz matrix.

Small rock sample with sprays of elongated, very lustrous, metallic, silvery-grey Tintinaite crystals cutting through white Quartz matrix.

Sprays of elongated, very lustrous, metallic, silvery-grey Tintinaite crystals (lead, copper, antimony, bismuth sulfide) cutting through white Quartz matrix.

Locality: Mária Mine, Rožňava, Rožňava County, Košice Region, Slovakia

#mineral #mineralogy #geology

03.01.2025 20:08 — 👍 4    🔁 1    💬 0    📌 0

Small rock with bright, silvery-grey crystals of Vikingite in a yellow-ish quartz matrix. There is a small red arrow made of tape pointing at the Vikingite crystals.

Small rock with bright, silvery-grey crystals of Vikingite in a yellow-ish quartz matrix. There is a small red arrow made of tape pointing at the Vikingite crystals.

Well formed bright, metallic, silvery-grey crystals of Vikingite (silver, lead, bismuth sulfide) in yellowish quartz matrix.

Locality: Siglitz adit, Siglitz - Bockhard Gold Mining District, Bad Gastein, St. Johann im Pongau District, Salzburg, Austria

#mineral #mineralogy #geology

03.01.2025 05:11 — 👍 1    🔁 0    💬 0    📌 0

Flat, cut slab of milky-white petrified wood with worm-like vein of deep purple Fluorite partially replacing it.

Flat, cut slab of milky-white petrified wood with worm-like vein of deep purple Fluorite partially replacing it.

Milky-white petrified wood that has been silicified, then partially replaced by deep purple Fluorite, which still preserves the original rings of the wood. This is the only locality known for fluorite replacing petrified wood.

Locality: Chemnitz Hilbersdorf, Saxony, Germany.

#mineralogy #mineral

29.12.2024 08:12 — 👍 1    🔁 0    💬 0    📌 0

Small rock containing thin veins and small isolated grains of metallic, steel-grey Holubite in a white crystalline matrix.

Thin veins of newly discovered (2023) bright, steel-grey Holubite (Ag3Pb6(Sb8Bi3)S24) in a quartz matrix from the type and currently only known locality.

Locality: Staročeské Lode, Kutná Hora, Central Bohemian Region, Czech Republic

#mineral #geology #mineralogy

17.12.2024 19:20 — 👍 3    🔁 0    💬 0    📌 0

Freestanding dendritic-shaped crystal of silvery-grey, metallic Acanthite on a white, plastic base.

Freestanding dendritic-shaped crystal of silvery-grey, metallic Acanthite on a white, plastic base.

Freestanding dendritic-shaped crystal of silvery-grey, metallic Acanthite on a white, plastic base.

Freestanding perfectly formed dendrite of silvery-grey Acanthite.

Locality: Imiter Mine, Tinghir Province, Drâa-Tafilalet Region, Morocco

15.12.2024 19:10 — 👍 2    🔁 0    💬 0    📌 0

Small rock sample containing brassy-yellow coloured Tučekite and silvery-grey coloured Ullmannite (both metallic) in a matrix of white quartz.

Small rock sample containing brassy-yellow coloured Tučekite and silvery-grey coloured Ullmannite (both metallic) in a matrix of white quartz.

Small rock sample containing brassy-yellow coloured Tučekite and silvery-grey coloured Ullmannite (both metallic) in a matrix of white quartz.

Two nickel sulfantinomides, Tučekite (brassy-yellow) and Ullmannite (silvery-grey), in a milky-white quartz matrix.

Locality: Adler Mine, Siegen, Siegerland, North Rhine - Westphalia, Germany

#mineral #geology #mineralogy

06.12.2024 07:17 — 👍 4    🔁 2    💬 0    📌 0