Discover and read the best of Twitter Threads about #calcite

Most recents (8)

Today #MinCup2020 is a battle of the carbonates.

Reasons to vote #Calcite: Perfect cleavage

Reasons to vote #Malachite: Specimen CC3353 from Copper Crescent in D.R. Congo.

📷 Crystal Classics Side view of an extremely p...Alternate side view of an e...Top view of an extremely ph...Cut bottom view of an extre...
Q: Lick?
A: Sure, #malachite is safe but boring for a quick taste.

Q: Nibble!
A: Ehhhh, not such a great idea. It’s soft (3.5-4 vs teeth at 5) & copper isn’t exactly a healthy snack.

Q: 🍆?
A: Pls no. While #Calcite bubbles in acid, malachite slowly dissolved into green goop.
Q: PERFECT cleavage? Really?

A: If you SMASHY-SMASHY calcite, it breaks on planes of weakness (cleavage planes) into 6-sided polyhedrons with diamond-shaped faces with 78° & 102° angles.

See:
📷: ??? stolen from old textbooks I think??? Calcite Crystal broken into...Calcite crystal and hammer ...
Read 3 tweets
#Malachite is gorgeous & I adorn myself with it regularly, but you're really going to want to vote for ##Lonsdaleite.

It forms in meteor impacts.
...from unusual meteors.

It's named for a #WomenInSTEM.
...from Ireland.
...who worked prison reform.
...after being imprisoned.
Whichever mineral survives will face off against #Calcite in Round 2.

Both calcite & malachite do fun things with acid (bubble; dissolve) and are iconic basic minerals to identify during intro geo lab classes. It'd be a solid, decent thread.

But lonsdaleite is SO WEIRD.
I don’t have the bandwidth to do proper campaign thread until I make it past a few deadlines, but futureYou will appreciate it if you keep #Lonsdalelite in the running until Round 2.
Read 3 tweets
It's 2020, the year where anything can happen.

The #MinCup2020 bracket is sticking to the rules with all official minerals. Voting starts September 1st.

Who will join legends #Olivine (2017), #Garnet (2018), & #IceMin (2019) to be this year's #champion? Bracket reading in order: B...
#MinCup2020 is kicking off quasi-alphabetically in a battle of peacock ore #Bornite vs poisonous red #Cinnabar

Pick your champion, make your arguments, and VOTE!
ROUND 1 MATCH 1 goes to #Cinnabar with a 8% lead over rainbow #Bornite! The same bracket, but with ...
Read 6 tweets
#MinCup2019 semifinals at @PMEUBC:

#Quartz: from Arkansas, USA
Amethyst: from Anahi Mine, Bolivia

#Calcite: detailed description of how 12% by mass is atmospheric carbon from 495 million years ago, what that tells us about ancient worlds, & how carbon is captured into crystal Large white hexagonal crystalsLarge purple hexagonal crystalsLarge blob of yellow trapezoidal crystals
If you can’t grow it, you mine it.

I’ve seen plenty of #MinCup2019 arguments that #quartz is in smartphones, but it doesn’t seem like many realize #calcite. Both semifinalists are in your phone display screen.
#Calcite & #quartz are battling it out in the semifinals of #MinCup2019. Quartz took a strong early lead, but calcite is creeping closer.

Quartz has never won despite the entire competition being founded to promote it.

I voted calcite.
Read 3 tweets
I’m totally amused how #quartz is catering the pity vote. All of #MinCup was created to make it feel special, yet every year other minerals win. Poor quartz.

Meanwhile #calcite is both fun & a climate indicator.
#Calcite is a mineral with neat optical properties, fizzes with acid, flags your attention when you stumble on to an ancient sea floor in the mountains, was a critical plot point for the premiere of #Stargate #SGU, and tracks climate.

But I lost a bet.
Whoo #quartz. Screenshot of a Stargate team in a desert investigating geology
So. #Quartz.

It’s most of Earth’s crust. If you’re only learning one mineral, quartz is a good default guess.

I can’t help with ID more than”uh, it’s hard?” unless it happens to be a pointy crystal, but I’ve never found those in the wild. It’s the white bits of granite. Large quartz crystal with plastic dinosaur
Read 10 tweets
We’re in the semi-finals of #MinCup2019 & I Have Opinions.

This is the year of #ClimateChange, the year we hit the tipping point of enough people caring to finally get to the large-scale hard work.

Our winner has to be ice or #calcite (tomorrow’s semi-finalist). #IceMin
#Olivine is a good mineral, a former 2017 #MinCup champion & one I campaigned for in past years.

It has so many cool quirks, including making green sand (!!). But it already won before.
Every year, people are startled to learn #IceMin is a mineral!

It’s naturally occurring, solid, has definite composition, & a repeating crystalline structure. As long as you find it in the wild, it checks every box.

Want it solid at room temperature? Ice VII trapped in diamond.
Read 5 tweets
Today’s #MinCup2019 is a face off between Very Interesting Properties. A translucent rock on a postcard creating a magnifying optical effect next to a small jar of black sand with a magnet stuck to it
Lots of minerals have neat optical effects, but #Ulexite is a bit different.

Light doesn’t pass straight through, like with #quartz or #halite (salt), nor does it have the birefringence of #calcite. Instead it’s a mineral of natural fibre optic channels transmitting light. Top view of the listed minerals on a postcardSide view of the same scene
#Ulexite grows as a bundle of fibers, each of which totally internally reflects light. It’s the same basic optics behind why diamond is sparkly.
Read 7 tweets

Related hashtags

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3.00/month or $30.00/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!