Barite is used as aggregates in concrete industry for the purpose of biological shielding against radiation. It is a highly dense non-metalic mineral. I wonder about the APF value of this mineral?
Atomic packing factor (APF) is the fraction of volume in a crystal structure that is occupied by constituent particles. It is a dimensionless quantity and always less than unity. By convention, APF is determined by assuming that atoms are rigid spheres.
For the hexagonal close-packed structure it is maximum.
Hexagonal close-packed (hcp): 0.74.
Face-centered cubic (fcc): 0.74 (also called cubic close-packed, ccp)
Body-centered cubic (bcc): 0.68.
Simple cubic: 0.52.
Diamond cubic: 0.34.
Thank you Latha,
As the packing increases the density of the mineral in turn, increases. That is why i asked this question, barite is a non-opaque dense mineral of density 4.5 close to that of ilmenite 4.72 which is an opaque mineral. I know that the atomic weight of barium is relatively high (around 137) but I do not know if the packing of barite is an additional cause for the high mineral density.
A straight forward calculation can be done using the equation for the sum presented in the following web page: https://msestudent.com/atomic-packing-factor/. After a short search, I see that Baryte has a an orthorhombic crystal system and that its corresponding space group is " Pnma ".You should also check materialsproject.org , there you can find accurate information regarding this crystal system and so you could easily calculate the atomic packing factor (APF).
- Badges
- Science topic
- Similar topics
- Methodology
- Research Methodology
- Research Papers