Repost from:
Mika McKinnon @mikamckinnon.bsky.social
Prefer bio to geo? Thbbbpft, but also:
1. #ikaite towers are a globally-unique ecosystem with cool critters!
https://arctichub.gl/unique-mineral-columns-in-ikkafjord-are-thriving-again/ (includes video). Bonus: They’re currently doing ok despite climate change & warming waters!
2. You can find it as white spots on frozen shrimp shells.
Repost from:
Dee Gardner @glacierpique.bsky.social
“They were able to identify the presence of two rather unique crystals on the surface of washed rind cheeses: struvite and ikaite.”
Thank you, Jasper Hill Farm. Thank you for not only throwing a raucous (and fiery) 15th anniversary party, but to also mark the occasion with the launch of the inaugural Jasper Hill Science Fair. It seemed inevitable that the revered farm, creamery and cellar would mark their anniversary with a smorgasbord of cheese and possibly … Continue reading "Paul Kinstedt: Blowing Minds, One Washed Rind Cheese at a Time"
#MinCup25 Round 1 Match 14: It's radioactive #cuprosklodowskite vs ephemeral #ikaite for today's match.
Vote: https://www.mineralcup.org/2025/vote/r1m14
Results: https://www.mineralcup.org/2025/results/r1m14
If you do access the link:
https://cds.dl.ac.uk/cgi-bin/rfm/crystalworks_trawl_new?8850_3368_5146
You might as well explore the full list of entrants. My two current favorites are Carpathite(3c) and Ikaite(7d)
Poor #Opal is languishing behind #Calcite in #MinCup23… And it always raises the question: should #Opal be in a mineral competition?
Nature doesn't categorise things as nicely as we might like, but it does provide a Teachable Opportunity™ to explain interesting things about minerals (& mineraloids) so I have reconstructed a previous #MinCup story (from the 𝔅𝚒🆁ⓓ𝚜𝑖🅃𝐞) to revisit an #Opal story for its fascinating geological and human history…
#Opal is associated with Australia with several #Opal mining locations in remote parts of the country such as White Cliffs in northwestern New South Wales.
White Cliffs is famous for its 'pineapple' opals - pseudomorphs of ikaite crystal clusters replaced by opal (𝑠𝑒𝑒 𝑝𝑟𝑒𝑡𝑡𝑦 𝑝𝑖𝑐𝑡𝑢𝑟𝑒 𝐴). They are very rare.
#Ikaite is a fascinating mineral in itself, but, alas, it lost in the first round of #MinCup22 so won’t be back for a while… But the cool thing (literally) about Ikaite is that it only forms at near freezing temperatures. Which means the Early Cretaceous aged claystone containing the #Opal pseudomorphs at White Cliffs was deposited in a polar ocean when Australia was much closer to the South Pole (𝑠𝑒𝑒 𝑝𝑟𝑒𝑡𝑡𝑦 𝑝𝑖𝑐𝑡𝑢𝑟𝑒 𝐵).
As some of you may have noticed, Australia is no longer polar. Opal forms with repeated wetting and drying as water with silica penetrates then evaporates from the claystone. And boy does White Cliffs know evaporation - at best it only has 20 cm of rain per year and averages 35°C in summer, typically peaking in the high 40's.
Opal was discovered at White Cliffs in 1884 and soon around 2000 miners were working the field. Conditions were extreme and building materials scarce. Many miners took to living in mine adits and shafts to escape the heat (𝑠𝑒𝑒 𝑝𝑟𝑒𝑡𝑡𝑦 𝑝𝑖𝑐𝑡𝑢𝑟𝑒 𝐶).
There are around 150 people in the township now and living underground is still the preferred option. It's a long drive to reach (even by Australian standards), but if you ever get a chance, it is an amazing place. There is even an underground motel you can stay at and the mine tours are fascinating. A few minutes fossicking around the old mullock heaps (𝑠𝑒𝑒 𝑝𝑟𝑒𝑡𝑡𝑦 𝑝𝑖𝑐𝑡𝑢𝑟𝑒 𝐷) is often enough to find tiny flakes of #Opal for your collection.
So go White Cliffs. Go #Opal!
This new paper by Phil Renforth and colleagues describes #OceanAlkalinityEnhancement (#OAE) for carbon dioxide removal (#CDR) using #ikaite or other hydrated carbonate minerals.
https://www.sciencedirect.com/science/article/pii/S2542435122005293
Bill Minarik
Mineral Cup & Ore Cup
Bob McMeeking
John Faithfull 🌍🇪🇺🏴🧡✊🏻✊🏿
Claudia Zahn
ksircombe
David Ho