Erika Anderson
LightNews LightNews
banner
andersonmineral.bsky.social
Erika Anderson
@andersonmineral.bsky.social
860 followers 120 following 830 posts
Former Curator of Mineralogy and Petrology. MSc in Volcanology. Views are my own.
Posts Replies Media Videos
andersonmineral.bsky.social
The Guess the Gem answer is topaz!! It can be naturally blue, as well as other colours, but there are artificial methods to get blue too. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
andersonmineral.bsky.social Erika Anderson @andersonmineral.bsky.social · 2d
Guess the Gem time!! What mineral do you think these gems are? Hint: the blue colour is from irradiation on the left and cobalt diffusion on the right. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
Two green gems in individual white plastic gem cases on white foam with the edges of other cases seen around them. They are mixed cut with the left one being bluer. At the Hunterian.
October 7, 2026 at 10:30 AM
andersonmineral.bsky.social
Guess the Gem time!! What mineral do you think these gems are? Hint: the blue colour is from irradiation on the left and cobalt diffusion on the right. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
Two green gems in individual white plastic gem cases on white foam with the edges of other cases seen around them. They are mixed cut with the left one being bluer. At the Hunterian.
October 6, 2026 at 10:33 AM
andersonmineral.bsky.social
A cute little rhomb of rhodochrosite, a shape you see in other minerals with a similar crystal structure. #MineralMonday #GeoscienceBluesky ⚒️🧪
Specimen of opaque pink rhomb of rhodochrosite on a base of rock composed of white quartz crystals and pyrite cubes. It sits on a wood background. At the Denver Museum of Nature and Science.
October 5, 2026 at 10:35 AM
Reposted by Erika Anderson
silicatefondue.fosstodon.org.ap.brid.gy
Quartz veins in slate show the deformation and material transport accompanying the growth of the Appalachians.

#mincup26 #quartz #quebec #Gaspésie
White quartz veins in a black slate. Several generations of veins show cross-cutting relationships and deformation within the rock. Siluro-Devonian Appalachians, Gaspe Penninsula, Quebec
September 30, 2026 at 6:43 PM
andersonmineral.bsky.social
A pretty little bivalve shell of the Pecten genus from Dublin. #FossilFriday ⚒️🧪
Fossil shell of a bivalve that has a rounded edge that then has ridges going to a central point on the opposite outer edge. The rock is grey on a beige background with a label with number 9 next to it. At the National Museum of Ireland.
October 2, 2026 at 11:00 AM
andersonmineral.bsky.social
A really cool massive halite crystal with a fluid inclusion!! Halite is a Mineral Cup favourite this year. #MineralMonday #MinCup26 #GeoscienceBluesky ⚒️🧪
September 28, 2026 at 10:36 AM
andersonmineral.bsky.social
Layers of bright yellow sulphur and crystals of celestine. It looks like a (non-edible) piece of cake! #MineralMonday #GeoscienceBluesky ⚒️🧪
Specimen showing four layers in a wedge shape: bright yellow sulphur on the bottom and second from the top, and grey celestine in the second from bottom and top. The top is paler crystals of celestine with a bit of massive sulphur. A blue nitrile hand holds it up on a grey background. At the Hunterian.
September 21, 2026 at 10:31 AM
andersonmineral.bsky.social
Triceratops horridus, a lot of people’s favourite dinosaur. Does everyone have a favourite? #FossilFriday⚒️🧪
Amounted Triceratops cast seen from the shoulders up showing its long horns. The lighting around it is purple. At Telus Spark.
September 18, 2026 at 11:01 AM
andersonmineral.bsky.social
The Guess the Gem answer is olivine!! It’s a mineral group that has the mineral species forsterite and fayalite. The gem variety is peridot. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
andersonmineral.bsky.social Erika Anderson @andersonmineral.bsky.social · 23d
Another Mineral Cup Guess the Gem!! What mineral or group do you think these gems are? Hint: it’s the first winner. #GuessTheGem #GeoscienceBluesky #MinCup26 ⚒️🧪💎
Two green gems on a black background. On the bottom left is a mixed cut gem and the top right is an octagonal step cut gem with the label 23 below it. At the Natural History Museum London.
September 16, 2026 at 10:34 AM
andersonmineral.bsky.social
Another Mineral Cup Guess the Gem!! What mineral or group do you think these gems are? Hint: it’s the first winner. #GuessTheGem #GeoscienceBluesky #MinCup26 ⚒️🧪💎
Two green gems on a black background. On the bottom left is a mixed cut gem and the top right is an octagonal step cut gem with the label 23 below it. At the Natural History Museum London.
September 15, 2026 at 10:35 AM
andersonmineral.bsky.social
Stress-free appreciation for cute little puffballs of okenite, no need to think about picking a favourite and voting since this mineral isn’t in this year’s Mineral Cup. #MineralMonday #GeoscienceBluesky ⚒️🧪
Specimen of grey rock with a cavity down the middle with green crystals and two white balls of thin okenite needles. Sits on a frosted plinth on a glass shelf off a grey wall. At the Royal Ontario Museum.
September 14, 2026 at 10:34 AM
andersonmineral.bsky.social
The skull of one of the largest dinosaurs, Patagotitan!! A close up look at what is at the top of a very long neck. #FossilFriday⚒️🧪🦕
A Patagotitan skull mounted on a white platform in a square with the edges lit up in white. The lighting around it is purple. At the Natural History Museum in London.
September 11, 2026 at 11:00 AM
andersonmineral.bsky.social
If you are attending SPNHC and missed my talk on using lessons from the past to curate the Anthropocene and the panel for the session, check out the recording, the discussion was great!! #GeoscienceBluesky #SPNHC2026 ⚒️🧪
September 10, 2026 at 10:16 PM
andersonmineral.bsky.social
The Guess the Gem answer is andalusite!! It’s a mineral that has the variety chiastolite that has inclusions that form a cross. #GuessTheGem #GeoscienceBluesky #MinCup26 ⚒️🧪💎
andersonmineral.bsky.social Erika Anderson @andersonmineral.bsky.social · Sep 8
A Mineral Cup Guess the Gem!! What mineral do you think these gems are? Hint: it’s a very recent Mineral Cup challenger. #GuessTheGem #GeoscienceBluesky #MinCup26 ⚒️🧪💎
Three green gems in a row on a grey background with the edge of a white label below. The middle is a large ovalish cut gem with a dark zone in the middle. The two on either side are rectangular with brownish zones at the corners. They are both colourless round brilliant cut gems and the left is bigger. At the Musée de Minéralogie Mines Paris.
September 9, 2026 at 11:10 AM
andersonmineral.bsky.social
A Mineral Cup Guess the Gem!! What mineral do you think these gems are? Hint: it’s a very recent Mineral Cup challenger. #GuessTheGem #GeoscienceBluesky #MinCup26 ⚒️🧪💎
Three green gems in a row on a grey background with the edge of a white label below. The middle is a large ovalish cut gem with a dark zone in the middle. The two on either side are rectangular with brownish zones at the corners. They are both colourless round brilliant cut gems and the left is bigger. At the Musée de Minéralogie Mines Paris.
September 8, 2026 at 10:32 AM
andersonmineral.bsky.social
I present to you on this Mineral Monday a very fine crystal of monazite, one of today’s Mineral Cup challengers. This one is from Joaquim Felício, Brazil. #MineralMonday #GeoscienceBluesky #MinCup26 ⚒️🧪
Brown crystal of monazite in a tray lined by white foam. At the Canadian Museum of Nature.
September 7, 2026 at 11:49 AM
Reposted by Erika Anderson
mineralcup.bsky.social
#MinCup26 Round 1 Match 6
It's a classic vs a newbie as the most common named mineral in the crust #Quartz is up against an exceedingly-rare sea foam-green mineral discovered just a few years ago #Asagiite.

VOTE: www.mineralcup.org/2026/vote-re...
RESULTS: www.mineralcup.org/2026/vote-re...
Split photo of clear quartz points radiating from a central point, with amethyst purple at some of the tips and cool mint green asagiite in mostly log-shaped crystals, with a few blobby bits.
September 6, 2026 at 12:00 AM
andersonmineral.bsky.social
As scary as this dude looks, Pachycephalosaurs are herbivorous (well maybe some insects too). #FossilFriday ⚒️🧪🦖
Mounted Pachycephalosaur skeleton cast seen from the shoulders up on the left side. You can see the skull dome and spikes around it and small teeth in its mouth. There’s a grey panel and a glass panel behind it. At the Royal Ontario Museum.
September 4, 2026 at 11:11 AM
andersonmineral.bsky.social
A big piece of watermelon tourmaline, a variety of the mineral elbaite. #MineralMonday #GeoscienceBluesky ⚒️🧪
Specimen of a wide specimen of watermelon tourmaline on a frosted plinth in front of a grey background. The crystals are pink on the bottom and the top goth is green. It sits on a grey background. At the Royal Ontario Museum.
August 31, 2026 at 10:31 AM
andersonmineral.bsky.social
The Guess the Gem answer is cubic zirconia!! It’s not a mineral because it’s not naturally occurring, but the mineral with the same chemical composition is baddeleyite. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
andersonmineral.bsky.social Erika Anderson @andersonmineral.bsky.social · Aug 25
Guess the Gem time! What do you think these gems are? Hint: it’s a common synthetic. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
Two gems in white gem cases on white foam surrounded by the edges of other gem cases. They are both colourless round brilliant cut gems and the left is bigger. At the Hunterian.
August 26, 2026 at 10:31 AM
andersonmineral.bsky.social
Guess the Gem time! What do you think these gems are? Hint: it’s a common synthetic. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
Two gems in white gem cases on white foam surrounded by the edges of other gem cases. They are both colourless round brilliant cut gems and the left is bigger. At the Hunterian.
August 25, 2026 at 10:31 AM
andersonmineral.bsky.social
This ball of marcasite is about the size of my hand. Massive!! #MineralMonday #GeoscienceBluesky ⚒️🧪
Specimen of small rectangular brownsish gold crystals of marcasite forming a large ball on a bed of white quartz crystals. It sits on a grey background. At the Musée de Minéralogie Mines Paris.
August 24, 2026 at 10:29 AM
andersonmineral.bsky.social
Gotta love the lit up Tyrannosaurus rex fossil skeleton!! #FossilFriday ⚒️🧪🦖
A mounted T. rex skeleton seen from the shoulders up on the left side with the bones lit up in neon green. At Telus Spark.
August 21, 2026 at 10:47 AM
andersonmineral.bsky.social
Finally got to see the SUE T. rex exhibit that @thomascullen.bsky.social worked on!!! Awesome to see this massive life sized model with dinosaur “lips”. #FossilFriday ⚒️🧪🦖
Full sized reconstruction of a Tyrannosaurus rex with a small dinosaur in its mouth in the middle of an exhibit room. At Telus Spark.
August 14, 2026 at 11:14 AM
andersonmineral.bsky.social
The Guess the Gem answer is fluorapatite!! It’s in teeth that have been exposed to fluoride which can help prevent tooth decay. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
andersonmineral.bsky.social Erika Anderson @andersonmineral.bsky.social · Jul 28
A Guess the Gem this week!! What mineral or group do you think these gems are? Hint: you can find it in your teeth. #GuessTheGem #GeoscienceBluesky ⚒️🧪💎
Two gems in white gem cases on white foam surrounded by the edges of other gem cases. The left one is a pale blue gem in the shape of a shield. On the right is a yellow square gem. At the Hunterian.
July 29, 2026 at 10:53 AM