#MinCup25 Round 1 Match 1: Hazardous (but useful!) #Chrysotile faces off against stunning gem #Pectolite. Do you pick the forbidden cotton candy, or the anti-pulverization beauty?
VOTE: https://www.mineralcup.org/2025/vote/r1m01
Check RESULTS: https://www.mineralcup.org/2025/results/r1m01
@MineralCup
I used to put up a page to follow the Mineral Cup with links to the crystal structures and details in #Mindat. But I have been reined in recently
https://cds.dl.ac.uk/cgi-bin/cw_page/examples_mincup23.html
You can see many of this years entries via the CrystalWorks link to the #365Minerals collection.
https://cds.dl.ac.uk/cgi-bin/cw_page/examples_rocks.html
I have decided to kick against the pricks and cobbled together a new page with reduced functionality
https://cds.dl.ac.uk/cgi-bin/rfm/crystalworks_trawl_new?8850_3368_5146
Entries not in #365Minerals are flagged with "X"
@MineralCup The structure of Pectolite and Chrysotile as displayed using JSmol within the CrystalWorks page.
https://cds.dl.ac.uk/cgi-bin/rfm/crystalworks_trawl_new?8850_3368_5146
Here is the crystal structure of Stibnite (Sb2S3). There are two slightly differing views generated by JSmol showing the arrangment of lath like rods oriented down the b-axis
Here is a view of the structure of Okenite. You are probably better off exploring the structure interactively using JSmol via CrystalWorks by going to the link:
https://cds.dl.ac.uk/cgi-bin/rfm/crystalworks_trawl_new?8850_3368_5146
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)
@MineralCup
Round 1 Match 7
Check out Sanidine(4a) and Hematite(4b): https://cds.dl.ac.uk/cgi-bin/rfm/crystalworks_trawl_new?8850_3368_5146
But only Sanidine (that and ten other members of the Feldspar group!) is in https://cds.dl.ac.uk/cgi-bin/cw_page/examples_rocks.html
See entry for 28th February in https://cds.dl.ac.uk/cgi-bin/cw_page/examples_365.html
A nice article on Fe2O3 by Helen Brand - "Hematite: a structure determined by Linus Pauling". Pauling determined the structure in 1925.
#MinCup25 #Hematite #Sanidine #365Minerals #Crystallography365
Helen's article is full of much interesting information both on Hematite itself and also on Pauling himself. Note the Hematite structure is Trigonal. Earlier determinations tended to display the structure with the rhombohedral setting later structures tended to use the hexagonal one.
Mineral Cup & Ore Cup
Bob McMeeking
John Faithfull 🌍🇪🇺🏴🧡✊🏻✊🏿