Nadine, Hunter of Rocks 💎
@nadwgab.bsky.social
Geologist | Mineralogy Curator @ the Natural History Museum, London | Creator of #365Minerals | Views are my own | She/Her
Posts about: #minerals #museums #geology #fossils #science #nature
Geology memes: #GeologistProblems
🐘 mas.to/@NadWGab
Posts about: #minerals #museums #geology #fossils #science #nature
Geology memes: #GeologistProblems
🐘 mas.to/@NadWGab
325 of #365Minerals 🧪⚒️
Barytocalcite:
- A barium calcium carbonate mineral
- Forms when hydrothermal fluids react with limestone
- Its type locality is Blagill Mine in Cumbria, England
- Named for its chemical composition #minerals
Barytocalcite:
- A barium calcium carbonate mineral
- Forms when hydrothermal fluids react with limestone
- Its type locality is Blagill Mine in Cumbria, England
- Named for its chemical composition #minerals
November 21, 2025 at 10:41 AM
325 of #365Minerals 🧪⚒️
Barytocalcite:
- A barium calcium carbonate mineral
- Forms when hydrothermal fluids react with limestone
- Its type locality is Blagill Mine in Cumbria, England
- Named for its chemical composition #minerals
Barytocalcite:
- A barium calcium carbonate mineral
- Forms when hydrothermal fluids react with limestone
- Its type locality is Blagill Mine in Cumbria, England
- Named for its chemical composition #minerals
324 of #365Minerals 🧪⚒️
Nepheline:
- A feldspathoid mineral
- Forms in volcanic rocks with low silica content
- Its name comes from the Greek word "νεφέλη/nephélē" (cloud) because it turns cloudy when exposed to strong acid #minerals
Nepheline:
- A feldspathoid mineral
- Forms in volcanic rocks with low silica content
- Its name comes from the Greek word "νεφέλη/nephélē" (cloud) because it turns cloudy when exposed to strong acid #minerals
November 20, 2025 at 10:35 AM
324 of #365Minerals 🧪⚒️
Nepheline:
- A feldspathoid mineral
- Forms in volcanic rocks with low silica content
- Its name comes from the Greek word "νεφέλη/nephélē" (cloud) because it turns cloudy when exposed to strong acid #minerals
Nepheline:
- A feldspathoid mineral
- Forms in volcanic rocks with low silica content
- Its name comes from the Greek word "νεφέλη/nephélē" (cloud) because it turns cloudy when exposed to strong acid #minerals
323 of #365Minerals 🧪⚒️
Oligoclase:
- A plagioclase feldspar mineral
- Sometimes classed as a variety of albite
- An important component of igneous rocks
- Its name comes from the Greek words "όλίγος/oligos" (little) and "κλάσις/klasis" (fracture) because of its cleavage #minerals
Oligoclase:
- A plagioclase feldspar mineral
- Sometimes classed as a variety of albite
- An important component of igneous rocks
- Its name comes from the Greek words "όλίγος/oligos" (little) and "κλάσις/klasis" (fracture) because of its cleavage #minerals
November 19, 2025 at 10:26 AM
323 of #365Minerals 🧪⚒️
Oligoclase:
- A plagioclase feldspar mineral
- Sometimes classed as a variety of albite
- An important component of igneous rocks
- Its name comes from the Greek words "όλίγος/oligos" (little) and "κλάσις/klasis" (fracture) because of its cleavage #minerals
Oligoclase:
- A plagioclase feldspar mineral
- Sometimes classed as a variety of albite
- An important component of igneous rocks
- Its name comes from the Greek words "όλίγος/oligos" (little) and "κλάσις/klasis" (fracture) because of its cleavage #minerals
322 of #365Minerals 🧪⚒️
Albite:
- A plagioclase feldspar mineral
- Forms in felsic igneous rocks
- First discovered in 1815 in Finnbo, Falun, Sweden
- Its name comes from the Latin word "albus" (white) because of its colour #minerals
Albite:
- A plagioclase feldspar mineral
- Forms in felsic igneous rocks
- First discovered in 1815 in Finnbo, Falun, Sweden
- Its name comes from the Latin word "albus" (white) because of its colour #minerals
November 18, 2025 at 11:45 AM
322 of #365Minerals 🧪⚒️
Albite:
- A plagioclase feldspar mineral
- Forms in felsic igneous rocks
- First discovered in 1815 in Finnbo, Falun, Sweden
- Its name comes from the Latin word "albus" (white) because of its colour #minerals
Albite:
- A plagioclase feldspar mineral
- Forms in felsic igneous rocks
- First discovered in 1815 in Finnbo, Falun, Sweden
- Its name comes from the Latin word "albus" (white) because of its colour #minerals
321 of #365Minerals 🧪⚒️
Biotite:
- A mica group mineral
- Forms in igneous and metamorphic rocks
- Can be used to date rocks
- Named after Jean-Baptiste Biot (1774-1862), a physicist who studied the optical properties of mica #minerals #MineralMonday
Biotite:
- A mica group mineral
- Forms in igneous and metamorphic rocks
- Can be used to date rocks
- Named after Jean-Baptiste Biot (1774-1862), a physicist who studied the optical properties of mica #minerals #MineralMonday
November 17, 2025 at 10:50 AM
321 of #365Minerals 🧪⚒️
Biotite:
- A mica group mineral
- Forms in igneous and metamorphic rocks
- Can be used to date rocks
- Named after Jean-Baptiste Biot (1774-1862), a physicist who studied the optical properties of mica #minerals #MineralMonday
Biotite:
- A mica group mineral
- Forms in igneous and metamorphic rocks
- Can be used to date rocks
- Named after Jean-Baptiste Biot (1774-1862), a physicist who studied the optical properties of mica #minerals #MineralMonday
It's the middle of November and I'm still pulling tomatoes and peppers off of my plants! 🌱🪴
November 16, 2025 at 3:49 PM
It's the middle of November and I'm still pulling tomatoes and peppers off of my plants! 🌱🪴
320 of #365Minerals 🧪⚒️
Tremolite:
- An amphibole group mineral
- The fibrous form is classed as asbestos
- Forms via the metamorphism of quartz and dolomite rich sediments
- Named after Tremola Valley in Tessin, Switzerland #minerals
Tremolite:
- An amphibole group mineral
- The fibrous form is classed as asbestos
- Forms via the metamorphism of quartz and dolomite rich sediments
- Named after Tremola Valley in Tessin, Switzerland #minerals
November 16, 2025 at 12:58 PM
320 of #365Minerals 🧪⚒️
Tremolite:
- An amphibole group mineral
- The fibrous form is classed as asbestos
- Forms via the metamorphism of quartz and dolomite rich sediments
- Named after Tremola Valley in Tessin, Switzerland #minerals
Tremolite:
- An amphibole group mineral
- The fibrous form is classed as asbestos
- Forms via the metamorphism of quartz and dolomite rich sediments
- Named after Tremola Valley in Tessin, Switzerland #minerals
319 of #365Minerals 🧪⚒️
Monazite:
- A phosphate mineral series with species rich in cerium, lanthanum, neodymium, samarium or gadolinium
- Radioactive due to thorium and sometimes uranium
- Its name comes from the Greek word "μονάζειν/monázein (to be alone) because of its isolated crystals #minerals
Monazite:
- A phosphate mineral series with species rich in cerium, lanthanum, neodymium, samarium or gadolinium
- Radioactive due to thorium and sometimes uranium
- Its name comes from the Greek word "μονάζειν/monázein (to be alone) because of its isolated crystals #minerals
November 15, 2025 at 7:49 AM
319 of #365Minerals 🧪⚒️
Monazite:
- A phosphate mineral series with species rich in cerium, lanthanum, neodymium, samarium or gadolinium
- Radioactive due to thorium and sometimes uranium
- Its name comes from the Greek word "μονάζειν/monázein (to be alone) because of its isolated crystals #minerals
Monazite:
- A phosphate mineral series with species rich in cerium, lanthanum, neodymium, samarium or gadolinium
- Radioactive due to thorium and sometimes uranium
- Its name comes from the Greek word "μονάζειν/monázein (to be alone) because of its isolated crystals #minerals
318 of #365Minerals 🧪⚒️
Scheelite:
- A calcium tungstate mineral
- An important ore of tungsten
- Forms during contact metamorphism and in hydrothermal veins
- Named after Carl Wilhelm Scheele (1742-1786), a Swedish chemist #minerals
Scheelite:
- A calcium tungstate mineral
- An important ore of tungsten
- Forms during contact metamorphism and in hydrothermal veins
- Named after Carl Wilhelm Scheele (1742-1786), a Swedish chemist #minerals
November 14, 2025 at 10:09 AM
318 of #365Minerals 🧪⚒️
Scheelite:
- A calcium tungstate mineral
- An important ore of tungsten
- Forms during contact metamorphism and in hydrothermal veins
- Named after Carl Wilhelm Scheele (1742-1786), a Swedish chemist #minerals
Scheelite:
- A calcium tungstate mineral
- An important ore of tungsten
- Forms during contact metamorphism and in hydrothermal veins
- Named after Carl Wilhelm Scheele (1742-1786), a Swedish chemist #minerals
317 of #365Minerals 🧪⚒️
Metavauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as vauxite, but a different crystal structure
- Named for its similarity to vauxite #minerals
Metavauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as vauxite, but a different crystal structure
- Named for its similarity to vauxite #minerals
November 13, 2025 at 1:03 PM
317 of #365Minerals 🧪⚒️
Metavauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as vauxite, but a different crystal structure
- Named for its similarity to vauxite #minerals
Metavauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as vauxite, but a different crystal structure
- Named for its similarity to vauxite #minerals
316 of #365Minerals 🧪⚒️
Vauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as metavauxite, but a different crystal structure
- Named after George Vaux Jr. (1863-1927), an American attorney and mineral collector #minerals
Vauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as metavauxite, but a different crystal structure
- Named after George Vaux Jr. (1863-1927), an American attorney and mineral collector #minerals
November 12, 2025 at 12:24 PM
316 of #365Minerals 🧪⚒️
Vauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as metavauxite, but a different crystal structure
- Named after George Vaux Jr. (1863-1927), an American attorney and mineral collector #minerals
Vauxite:
- A phosphate mineral
- Forms via the alteration of apatite
- Has the same formula as metavauxite, but a different crystal structure
- Named after George Vaux Jr. (1863-1927), an American attorney and mineral collector #minerals
315 of #365Minerals 🧪⚒️
Picromerite:
- A hydrous sulphate mineral
- Forms in bedded salt deposits in the ocean and as a sublimate in fumaroles
- Its name comes from the Greek words "πικρός/pikros" (bitter) and "μέρος/meros" (part) because it contains magnesium #minerals
Picromerite:
- A hydrous sulphate mineral
- Forms in bedded salt deposits in the ocean and as a sublimate in fumaroles
- Its name comes from the Greek words "πικρός/pikros" (bitter) and "μέρος/meros" (part) because it contains magnesium #minerals
November 11, 2025 at 12:41 PM
315 of #365Minerals 🧪⚒️
Picromerite:
- A hydrous sulphate mineral
- Forms in bedded salt deposits in the ocean and as a sublimate in fumaroles
- Its name comes from the Greek words "πικρός/pikros" (bitter) and "μέρος/meros" (part) because it contains magnesium #minerals
Picromerite:
- A hydrous sulphate mineral
- Forms in bedded salt deposits in the ocean and as a sublimate in fumaroles
- Its name comes from the Greek words "πικρός/pikros" (bitter) and "μέρος/meros" (part) because it contains magnesium #minerals
314 of #365Minerals 🧪⚒️
Riebeckite:
- An amphibole group mineral
- Forms in some volcanic rocks and schists
- Blue asbestos (crocidolite) is fibrous riebeckite
- Named after Emil Riebeck (1853-1885), mineralogist and explorer #minerals #MineralMonday
Riebeckite:
- An amphibole group mineral
- Forms in some volcanic rocks and schists
- Blue asbestos (crocidolite) is fibrous riebeckite
- Named after Emil Riebeck (1853-1885), mineralogist and explorer #minerals #MineralMonday
November 10, 2025 at 10:43 AM
314 of #365Minerals 🧪⚒️
Riebeckite:
- An amphibole group mineral
- Forms in some volcanic rocks and schists
- Blue asbestos (crocidolite) is fibrous riebeckite
- Named after Emil Riebeck (1853-1885), mineralogist and explorer #minerals #MineralMonday
Riebeckite:
- An amphibole group mineral
- Forms in some volcanic rocks and schists
- Blue asbestos (crocidolite) is fibrous riebeckite
- Named after Emil Riebeck (1853-1885), mineralogist and explorer #minerals #MineralMonday
313 of #365Minerals 🧪⚒️
Alunite:
- A sulphate mineral
- A source of aluminium and potassium
- Forms when acid solutions alter potassium-rich volcanic rocks
- Its name comes from the Latin word "alunit" (alum) #minerals
Alunite:
- A sulphate mineral
- A source of aluminium and potassium
- Forms when acid solutions alter potassium-rich volcanic rocks
- Its name comes from the Latin word "alunit" (alum) #minerals
November 9, 2025 at 10:28 AM
313 of #365Minerals 🧪⚒️
Alunite:
- A sulphate mineral
- A source of aluminium and potassium
- Forms when acid solutions alter potassium-rich volcanic rocks
- Its name comes from the Latin word "alunit" (alum) #minerals
Alunite:
- A sulphate mineral
- A source of aluminium and potassium
- Forms when acid solutions alter potassium-rich volcanic rocks
- Its name comes from the Latin word "alunit" (alum) #minerals
312 of #365Minerals 🧪💎
Phenakite:
- A silicate mineral
- Forms in pegmatite veins and mica-schists
- Sometimes used as a gemstone
- Its name comes from the Greek word "φέναξ/phénax" (deceiver) because it looks like quartz #minerals
Phenakite:
- A silicate mineral
- Forms in pegmatite veins and mica-schists
- Sometimes used as a gemstone
- Its name comes from the Greek word "φέναξ/phénax" (deceiver) because it looks like quartz #minerals
November 8, 2025 at 1:05 PM
312 of #365Minerals 🧪💎
Phenakite:
- A silicate mineral
- Forms in pegmatite veins and mica-schists
- Sometimes used as a gemstone
- Its name comes from the Greek word "φέναξ/phénax" (deceiver) because it looks like quartz #minerals
Phenakite:
- A silicate mineral
- Forms in pegmatite veins and mica-schists
- Sometimes used as a gemstone
- Its name comes from the Greek word "φέναξ/phénax" (deceiver) because it looks like quartz #minerals
311 of #365Minerals 🧪⚒️
Benstonite:
- A carbonate mineral containing barium
- Fluoresces red under UV and x-rays
- Forms in baryte deposits and in some carbonatites
- Named after Orlando J. Benston (1901-1966) an American ore metallurgist who collected the first specimens #minerals
Benstonite:
- A carbonate mineral containing barium
- Fluoresces red under UV and x-rays
- Forms in baryte deposits and in some carbonatites
- Named after Orlando J. Benston (1901-1966) an American ore metallurgist who collected the first specimens #minerals
November 7, 2025 at 10:02 AM
311 of #365Minerals 🧪⚒️
Benstonite:
- A carbonate mineral containing barium
- Fluoresces red under UV and x-rays
- Forms in baryte deposits and in some carbonatites
- Named after Orlando J. Benston (1901-1966) an American ore metallurgist who collected the first specimens #minerals
Benstonite:
- A carbonate mineral containing barium
- Fluoresces red under UV and x-rays
- Forms in baryte deposits and in some carbonatites
- Named after Orlando J. Benston (1901-1966) an American ore metallurgist who collected the first specimens #minerals
310 of #365Minerals 🧪⚒️
Pyrolusite:
- Mineral form of manganese dioxide
- A very common manganese mineral
- An important manganese ore
- Used as a pigment in ancient cave paintings
- Forms in oxidised manganese-bearing hydrothermal deposits #minerals
Pyrolusite:
- Mineral form of manganese dioxide
- A very common manganese mineral
- An important manganese ore
- Used as a pigment in ancient cave paintings
- Forms in oxidised manganese-bearing hydrothermal deposits #minerals
November 6, 2025 at 10:14 AM
310 of #365Minerals 🧪⚒️
Pyrolusite:
- Mineral form of manganese dioxide
- A very common manganese mineral
- An important manganese ore
- Used as a pigment in ancient cave paintings
- Forms in oxidised manganese-bearing hydrothermal deposits #minerals
Pyrolusite:
- Mineral form of manganese dioxide
- A very common manganese mineral
- An important manganese ore
- Used as a pigment in ancient cave paintings
- Forms in oxidised manganese-bearing hydrothermal deposits #minerals
309 of #365Minerals 🧪⚒️
Ruby:
- The red/pink variety of corundum
- Its colour is caused by chromium
- Heat treatment can improve its colour
- 9 on the Mohs hardness scale
- Its name comes from the Latin word "ruber" (red) #minerals
Ruby:
- The red/pink variety of corundum
- Its colour is caused by chromium
- Heat treatment can improve its colour
- 9 on the Mohs hardness scale
- Its name comes from the Latin word "ruber" (red) #minerals
November 5, 2025 at 10:41 AM
309 of #365Minerals 🧪⚒️
Ruby:
- The red/pink variety of corundum
- Its colour is caused by chromium
- Heat treatment can improve its colour
- 9 on the Mohs hardness scale
- Its name comes from the Latin word "ruber" (red) #minerals
Ruby:
- The red/pink variety of corundum
- Its colour is caused by chromium
- Heat treatment can improve its colour
- 9 on the Mohs hardness scale
- Its name comes from the Latin word "ruber" (red) #minerals
308 of #365Minerals 🧪⚒️
Diopside:
- Pyroxene mineral
- Forms in ultramafic igneous rocks, xenoliths & metamorphic rocks
- Can turn into chrysotile when hydrothermally altered
- Name comes from the Greek "dis" (twice) & "òpsè" (face) because its vertical prism can be orientated in two ways #minerals
Diopside:
- Pyroxene mineral
- Forms in ultramafic igneous rocks, xenoliths & metamorphic rocks
- Can turn into chrysotile when hydrothermally altered
- Name comes from the Greek "dis" (twice) & "òpsè" (face) because its vertical prism can be orientated in two ways #minerals
November 4, 2025 at 11:07 AM
308 of #365Minerals 🧪⚒️
Diopside:
- Pyroxene mineral
- Forms in ultramafic igneous rocks, xenoliths & metamorphic rocks
- Can turn into chrysotile when hydrothermally altered
- Name comes from the Greek "dis" (twice) & "òpsè" (face) because its vertical prism can be orientated in two ways #minerals
Diopside:
- Pyroxene mineral
- Forms in ultramafic igneous rocks, xenoliths & metamorphic rocks
- Can turn into chrysotile when hydrothermally altered
- Name comes from the Greek "dis" (twice) & "òpsè" (face) because its vertical prism can be orientated in two ways #minerals
307 of #365Minerals 🧪⚒️
Hummerite:
- A potassium magnesium vanadate mineral
- Forms via the leaching of vanadium oxide ores
- Named after its type locality Hummer Mine in Paradox Valley, Colorado, USA #minerals #MineralMonday
Hummerite:
- A potassium magnesium vanadate mineral
- Forms via the leaching of vanadium oxide ores
- Named after its type locality Hummer Mine in Paradox Valley, Colorado, USA #minerals #MineralMonday
November 3, 2025 at 12:51 PM
307 of #365Minerals 🧪⚒️
Hummerite:
- A potassium magnesium vanadate mineral
- Forms via the leaching of vanadium oxide ores
- Named after its type locality Hummer Mine in Paradox Valley, Colorado, USA #minerals #MineralMonday
Hummerite:
- A potassium magnesium vanadate mineral
- Forms via the leaching of vanadium oxide ores
- Named after its type locality Hummer Mine in Paradox Valley, Colorado, USA #minerals #MineralMonday
306 of #365Minerals 🧪⚒️
Leadhillite:
- A carbonate mineral
- Has a high density since it contains lead (~2.5 times more dense than quartz)
- Can be yellow, blue or green
- Forms in the oxidised zone of lead deposits
- Named after Leadhills in Scotland, its type locality #minerals #MineralMonday
Leadhillite:
- A carbonate mineral
- Has a high density since it contains lead (~2.5 times more dense than quartz)
- Can be yellow, blue or green
- Forms in the oxidised zone of lead deposits
- Named after Leadhills in Scotland, its type locality #minerals #MineralMonday
November 3, 2025 at 12:37 PM
306 of #365Minerals 🧪⚒️
Leadhillite:
- A carbonate mineral
- Has a high density since it contains lead (~2.5 times more dense than quartz)
- Can be yellow, blue or green
- Forms in the oxidised zone of lead deposits
- Named after Leadhills in Scotland, its type locality #minerals #MineralMonday
Leadhillite:
- A carbonate mineral
- Has a high density since it contains lead (~2.5 times more dense than quartz)
- Can be yellow, blue or green
- Forms in the oxidised zone of lead deposits
- Named after Leadhills in Scotland, its type locality #minerals #MineralMonday
305 of #365Minerals 🧪⚒️
Sylvanite:
- A telluride mineral
- Contains gold and silver
- Forms in hydrothermal vein deposits
- Named after sylvanium, the obsolete name for the element tellurium. Its name is also partially derived from Transylvania, where it was discovered #minerals #MineralMonday
Sylvanite:
- A telluride mineral
- Contains gold and silver
- Forms in hydrothermal vein deposits
- Named after sylvanium, the obsolete name for the element tellurium. Its name is also partially derived from Transylvania, where it was discovered #minerals #MineralMonday
November 3, 2025 at 12:34 PM
305 of #365Minerals 🧪⚒️
Sylvanite:
- A telluride mineral
- Contains gold and silver
- Forms in hydrothermal vein deposits
- Named after sylvanium, the obsolete name for the element tellurium. Its name is also partially derived from Transylvania, where it was discovered #minerals #MineralMonday
Sylvanite:
- A telluride mineral
- Contains gold and silver
- Forms in hydrothermal vein deposits
- Named after sylvanium, the obsolete name for the element tellurium. Its name is also partially derived from Transylvania, where it was discovered #minerals #MineralMonday
304 of #365Minerals 🧪⚒️
Hematite:
- Very common iron oxide mineral
- Its red powder is used as a pigment
- Forms in a variety of volcanic, sedimentary & metamorphic environments
- Its name comes from the Greek words "αιματίτις λίθος/aematitis lithos" (blood stone) because of its red colour #minerals
Hematite:
- Very common iron oxide mineral
- Its red powder is used as a pigment
- Forms in a variety of volcanic, sedimentary & metamorphic environments
- Its name comes from the Greek words "αιματίτις λίθος/aematitis lithos" (blood stone) because of its red colour #minerals
October 31, 2025 at 11:34 AM
304 of #365Minerals 🧪⚒️
Hematite:
- Very common iron oxide mineral
- Its red powder is used as a pigment
- Forms in a variety of volcanic, sedimentary & metamorphic environments
- Its name comes from the Greek words "αιματίτις λίθος/aematitis lithos" (blood stone) because of its red colour #minerals
Hematite:
- Very common iron oxide mineral
- Its red powder is used as a pigment
- Forms in a variety of volcanic, sedimentary & metamorphic environments
- Its name comes from the Greek words "αιματίτις λίθος/aematitis lithos" (blood stone) because of its red colour #minerals
303 of #365Minerals 🧪⚒️
Glauconite:
- A mica group mineral
- Forms in marine environments
- Turns yellow when oxidised
- The "green earth" pigment is made from glauconite
- Its name comes from the Greek word "γλαυκός/glaukos" (blue-green) because of its colour #minerals
Glauconite:
- A mica group mineral
- Forms in marine environments
- Turns yellow when oxidised
- The "green earth" pigment is made from glauconite
- Its name comes from the Greek word "γλαυκός/glaukos" (blue-green) because of its colour #minerals
October 30, 2025 at 10:24 AM
303 of #365Minerals 🧪⚒️
Glauconite:
- A mica group mineral
- Forms in marine environments
- Turns yellow when oxidised
- The "green earth" pigment is made from glauconite
- Its name comes from the Greek word "γλαυκός/glaukos" (blue-green) because of its colour #minerals
Glauconite:
- A mica group mineral
- Forms in marine environments
- Turns yellow when oxidised
- The "green earth" pigment is made from glauconite
- Its name comes from the Greek word "γλαυκός/glaukos" (blue-green) because of its colour #minerals