4 ms·

Also not a mineral expert -- I didn't really understand anything from Wikipedia's description, "monoclinic with space group I2/c, and is isostructural with...".

Also not a mineral expert -- I didn't really understand anything from Wikipedia's description, "monoclinic with space group I2/c, and is isostructural with...". But since it's naturally occuring, perhaps even existing bismuth mines elsewhere have more of these rare grains, if one knows how to look for them.

gus_massa 2y ago
The atoms in crystasl are organized in small repeated "cells". Monoclinic means that each cell has the shape of a small slanted brick https://en.wikipedia.org/wiki/Monoclinic https://en.wikipedia.org/wiki/Monoclinic . Isostructural means that other minerals have the atoms in the same arrangement. Space group I2/c is more detailed info about where the atoms are in the small cells/slanted brick. I have no idea what it exactly means. It's a name very specific to cristalographers, sometimes the same group has a different name in math or phisics, and sometimes nobody has a similar problem to be interested in that group. You can try to take a look at https://en.wikipedia.org/wiki/Crystallographic_point_group https://en.wikipedia.org/wiki/Crystallographic_point_group Aparently there are 6 (six!) naming conventions, but I can't find I2/c to save my life. And Google didn't help either. (I'd glad if anyone can give more info.)
- gilleain 2y ago
  So a physics stack exchange question (https://physics.stackexchange.com/questions/221440/space-group-setting-of-a-crystal-structure https://physics.stackexchange.com/questions/221440/space-gro...) led me to a paper (https://nvlpubs.nist.gov/nistpubs/jres/107/4/j74mig.pdf https://nvlpubs.nist.gov/nistpubs/jres/107/4/j74mig.pdf) that discusses the difference between C-centered (base-centered) cells and I-centered (body centered cells). Long story short, I think I2/c is conventionally C2/c - https://www.globalsino.com/EM/page1891.html https://www.globalsino.com/EM/page1891.html
- jnurmine 2y ago
  This was very helpful, thanks! It's often the very domain-specific language that hides (at least on the surface) rather simple concepts. I do appreciate how confusing software engineering terminology must seem to outsiders... zombies, chicken bits, duck typing, core affinity, etc.
bcraven 2y ago
If you think Wikipedia is hard to parse, try the womderful site Mindat: https://www.mindat.org/min-46909.html https://www.mindat.org/min-46909.html

gus_massa 2y ago

The atoms in crystasl are organized in small repeated "cells". Monoclinic means that each cell has the shape of a small slanted brick https://en.wikipedia.org/wiki/Monoclinic https://en.wikipedia.org/wiki/Monoclinic . Isostructural means that other minerals have the atoms in the same arrangement. Space group I2/c is more detailed info about where the atoms are in the small cells/slanted brick. I have no idea what it exactly means. It's a name very specific to cristalographers, sometimes the same group has a different name in math or phisics, and sometimes nobody has a similar problem to be interested in that group. You can try to take a look at https://en.wikipedia.org/wiki/Crystallographic_point_group https://en.wikipedia.org/wiki/Crystallographic_point_group Aparently there are 6 (six!) naming conventions, but I can't find I2/c to save my life. And Google didn't help either. (I'd glad if anyone can give more info.)

gilleain 2y ago
So a physics stack exchange question (https://physics.stackexchange.com/questions/221440/space-group-setting-of-a-crystal-structure https://physics.stackexchange.com/questions/221440/space-gro...) led me to a paper (https://nvlpubs.nist.gov/nistpubs/jres/107/4/j74mig.pdf https://nvlpubs.nist.gov/nistpubs/jres/107/4/j74mig.pdf) that discusses the difference between C-centered (base-centered) cells and I-centered (body centered cells). Long story short, I think I2/c is conventionally C2/c - https://www.globalsino.com/EM/page1891.html https://www.globalsino.com/EM/page1891.html
jnurmine 2y ago
This was very helpful, thanks! It's often the very domain-specific language that hides (at least on the surface) rather simple concepts. I do appreciate how confusing software engineering terminology must seem to outsiders... zombies, chicken bits, duck typing, core affinity, etc.

bcraven 2y ago

If you think Wikipedia is hard to parse, try the womderful site Mindat: https://www.mindat.org/min-46909.html https://www.mindat.org/min-46909.html