#Calcite hands down. Opal looks beautiful but so can good 'ol trigonal CaCO3. And it can do so much more. See my threads of the past MinCups https://x.com/KleinerGeologe/status/1436807094670397440?s=20… (last post of the thread because you can't see the rest from the first for some reason)

After the deadheat of last match, we can all relax for #MinCup23 Round 1 Match 11 where… oh no, it’s two favourites! #Calcite vs #Opal One fights on, the other is eliminated for 2024. Eek!! Vote: https://www.mineralcup.org/2023/campaigns/round-1-match-11… Results: https://www.mineralcup.org/results/round-1-match-11…

#TeamCalcite no question. As a sediment it preserves fossils and records the paleoenvironment through oxygen/cabron isotopes. Although limestone can be good enough for decorative fassades, countertop people might find the metamorphic marble more appealing. Also artists.

I rest my case #calcite #MinCup

Today on GeoScience Twitter, I'm gonna talk about rocks made of bacon. Or so you may think while looking on this special calc-sinter.