Some #corundum on Earth is older than our solar-system; these pre-solar grains are found in some chondritic meteorites. Oxygen isotopes reveal that they formed in the puffed-off atmospheres of old red-giant stars. From Frisch et al. 2005.
#MinCup23 #Cosmochemistry #Meteorites

#TeamLawsonite for today's round of #MinCup23. Okay, #Corundum is a nice mineral, but I'll give #Lawsonite some love just because it's bringing back a #ThinSectionThursday on a friday :)

Link to vote: https://www.mineralcup.org/2023/campaigns/round-1-match-8

@MineralCup Hope one or more volunteers see this comment from me just now as I finished voting for #Corundum I’m having a hard time easily finding the links to daily matches. Usually have to search hashtags for voters who are posting about minerals in order to find someone who also shares the daily link. Help! #MinCup23

Today, it's all about #corundum for me. The aluminium oxide (Al2O3) is used for a lot of white ceramic materials for high temperature applications in our lab, but it can also go bling-bling. With the right impurities, #corundum becomes 🟦 sapphire or 🟥 ruby. Useful & beautiful!

#corundum as a gemstone is cool! As a mineral... I mean it has some industrial uses as an abrasive, but other than that... 🤷🏻

#lawsonite is metamorphic, characteristic of low heat and high pressure at plate boundaries, and very hydrated - so it tends to drag water molecules around with it. You'll also find other blueschist minerals like #kyanite where lawsonite often is. (c) #MinCup23

Okay, if I was voting on about any other campaign line this year, #corundum vs #lawsonite would be easier. Or at least probably less boring. 😂

Neither of them are chaotic at all - as far as minerals go, they're upright, goody-two-shoes grasping their pearls (carefully, because they're both much higher on the mohs scale than pearls!) at how chaotic some of these other minerals are. (c) #MinCup23

Sapphirine's type locality is in western Greenland, south of Nuuk, which is where the mineral was discovered in 1809 by Karl Giesecke.

It was named due to its blue color being similar to sapphire, a different, associated mineral (#corundum, aluminum oxide).

An amazing amount of information can be found about #sapphirine at MinDat:
https://www.mindat.org/min-3531.html
a non-profit mineral data base founded in 2000 by Jolyon Ralph (who is on Mastodon at @jolyon).

#MinCup23 #Minerals #Greenland

#astronomy #exoplanets #WASP121b #Hubble #corundum An article published in the journal "Nature Astronomy" reports the results of a new study on the exoplanet WASP-121b, an ultrahot Jupiter considered one of the planets with the most extreme conditions known.

https://english.tachyonbeam.com/2022/02/23/on-the-exoplanet-wasp-121b-perhaps-rubies-and-sapphires-rain-down/