#Mincup25 Teams #Calcite #Azurite #silver #chrysotile #okenite #wavellite #pollucite #nontronite #padddlewheelite #leucite #jeremejevite #zunyite #thortveitite #topaz #ikaite #sanidine
"The losing minerals are crossed out" - and cross!
www.mineralcup.org/2025/bracket
What to do?
We can... 1/2
According to gemrockauctions.com #Leucite is used in both fertilizer (it contains potassium) & in dental ceramics.
So this is a fragile rock doing the best it can to be useful.
Meanwhile...
Today's #mincup competitors are going to take more than just a post or 2 to discuss. We have soft & white #leucite versus green in visual & blue under UV #carpathite, which is the crystalized form of Coronene.
From appearance alone, the striking #carpathite is the winner
But let's look deeper. A 🧵
Those are the best clear crystals I’ve seen of #Leucite ! Sadly I just saw the loss to #Carpathite
The geology and history of the Leucite Hills in Wyoming tipped me over to #Leucite. I’m on Madyodon for my main social media and active followers there for #MinCup25 have provided awesome links to the scientific properties that were compelling.
A photomicrograph of a mixture of leucite and glass used in dental porcelain because the thermal expansion of leucite matches that of the metal post implant. From: J.R. Mackert et al (1986)The effect of the leucite transformation on dental porcelain expansion, Dental Materials, Volume 2: 32-36
#Leucite is used to make dental porcelain (or rather, leucite + glass from melting feldspar incongruently). Thiis is becuase it:
is immune system compatible
is machinable
is fracture resistant with low porosity
it doesn't easily stain or discolour
and most […]
[Original post on fosstodon.org]
Reading up on both #Carpathite and #Leucite I really like them both. I tend to favor minerals that have volcanoes 🌋 in their origin stories, so that has me tipping towards leucite. However, I remain unconvinced, and with six hours to go, I’m open to all arguments. #MinCup25 (Pix from mindat.org)
I love Mineral Cup for educating me about minerals I'd never heard of before.
But I'll still vote for shallow reasons. #Carpathite is more colorful than #Leucite, so even though leucite is also "white garnet", I'm voting for carpathite.
#MinCup25
#Leucite bc my feldspathoid loyalties run strong. Fun Wikipedia fact René Just Haüy (of #haüyne fame) named this mineral ‘amphigène’ #MinCup25
#Leucite
3. Transformation is clearly the party trick, but what does it look like? Crystal structure only or anything macro (beyond striations)? Is it gradual or abrupt?
4. Twin lamellae & striations are distinct, but how & what’s the implication of having both? (Bonus: labradorescence?)
I choose the feldspathoid #leucite over the hydrocarbon mineral. Won’t catch me voting for a hydrocarbon #MinCup25
Boar's Tusk in the Leucite Hills, Wyoming. From Wikimedia, photo by James St. John.
A thin section of leucite in cross-polars, showing the twinning formed when high-temperature isometric crystals transitions to tetragonal symmetry. From Smith College, https://www.science.smith.edu/geosciences/petrology/petrography/leucite/leucite.html
Leucite has a range of volcanic hills named after it, see:
https://www.geowyo.com/leucite-hills.html
These are strange, high potassium lamproites from the mantle, only 1-2 million years old.
Match that, organic goo #carpathite !
Students at Smith College […]
[Original post on fosstodon.org]
Hoy es el 6to Match de #MinCup25 dónde el mineral orgánico Carpatita #Carpathite se enfrenta a la Leucita #Leucite con una estructura que cambia reversiblemente con la temperatura.
Yo voté Leucita, vos qué votás? 👇🏻
www.mineralcup.org/2025/vote/r1...
#MinCup25 Round 1 Match 6: 🔷 #Carpathite, the rare hydrocarbon mineral that fluoresces blue, vs ⚪ #Leucite, the volcanic feldspathoid
#minerals #mineralogy
#MinCup25 #r1m6
Thus is a tough one. #caroathite v #leucite
Organic mineral versus igneous potassium aluminum and silica.
Lots to love on both sides here.
Leucite crystal source: https://www.mineralatlas.eu/lexikon/index.php/MineralData?mineral=Leucite
"Flammable" 🥸
First, organic chemists convinced inorganic chemists that cooking organic ligands is "inorganic coordination chemistry" and now they try to conquer mineralogy. What comes next? Sacccharose crystals?
Vote strategic! Vote inorganic! Vote #leucite! #mincup
I'm voting #leucite because it can pseudomorph to kaolinite - which is not smectite, but almost, and I didn't have time to make a cartoon today, so here's an old one 😉
Light gray volcanic matrix holds adorable trapezohedral leucite crystals.
Wood block form and dark gray leucite crystal in trapezohedral habit.
Today's #MinCup25 #leucite!
Volcanic.
Adorable crystal shape.
Vesuvius type local.
Traps xls in growth zones.
Sometimes shows labradoresce.
Crystallizes in one habit...changes when cooled...then goes back to the original habit when reheated.
Doesn't catch on fire.
📷 mine from Cranbrook
#Leucite does some eerie stuff with its coloration.
It might be a milky portal to a strange, indescribable universe.
Who can say?
(Not the geologists.)
So, um. Vote for this rock.
#Mincup25
I am voting for shape shifter #Leucite which can go from cubic at high temps to tetragonal at lower temps and transformation is reversible! #Mincup25
Able to be scratched by household dust? #Leucite sounds as fragile as I’m feeling today! Vote #Leucite in #MinCup25
Four mineral specimens. Top row has spodumene (gray and rocky) and ilvaite (dark black and dramatic columns). Bottom row has cancrinite (yellow with gray and black blotches, kinda like a tortoiseshell sitting in the sun) and leucite (a grey base with a crystal structure that looks like it could be picked up and rolled like a d20)
And for Round 1, Match 6 I could only find #leucite which I will share along with its neighbors spodumene, ilvaite, and cancrinite.
#MinCup25
#MinCup25SideQuest
#MinCup25 Round 1 Match 6: Brace for oddness in a match between one of the very few hydrocarbon minerals #carpathite and the temperature-flipping mineral #leucite.
Vote: www.mineralcup.org/2025/vote/r1...
Results: www.mineralcup.org/2025/results...
