@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

The #365Minerals entry for today (3rd August) is Millerite ( β-NiS)

🔗 https://cds.dl.ac.uk/cgi-bin/cw_page/examples_rocks.html

Actually the α-NiS dimorph is also included in the CrystalWorks list. But this form is in fact the rare, recently identified mineral Crowningshieldite.

The α and β form are also given as the 20th July entry in the #Crystallography365 collection "Nickel sulfide: a smashing crystal structure"

🔗 https://cds.dl.ac.uk/cgi-bin/cw_page/examples_365.html

Both are worth checking out

If eligible you can register via the CrystalWorks homepage. If you are already a registered user, you may find you have to reset your password if you have not done so recently.

Anybody is free to access the Crystallographic Open Database.
There are also a number of other open crystal structure based pages. These include the #365Minerals and #Crystallography365 collections.

🔗the CrystalWorks homepage: https://cds.dl.ac.uk/
🔗open access CrystalWorks pages: https://cds.dl.ac.uk/cgi-bin/cw_page/link_to_cworks.html