Home > Kalahari Manganese Field – March 18 > MS0904 Portlandite
Portlandite - Sold
- Wessels mine
- Kalahari Manganese Field
- Northern Cape Province
- South Africa
- 4.9 by 2.9 by 1.1 cm – Miniature specimen (fits into a 5 cm cube)
Portlandite is simple calcium hydroxide. Tilley (1933) named the mineral portlandite since the artificial compound forms by hydration of Portland cement. Although portlandite has a modest solubility in water, it is sufficiently stable to store in a humid climate. The mineral has hexagonal symmetry and is a member of the brucite group. It forms soft foliated masses, here stark white. This is rare material. This specimen carries a Carter Rich label.
