from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A white, pale pink, or pale green crystalline mineral, essentially KCa4Si8O20(F,OH)·8H2O.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of several forms of a pale pink or green mineral being a mixed fluoride and silicate of potassium and calcium.
from the GNU version of the Collaborative International Dictionary of English
- n. A mineral relating to the zeolites, usually occurring in square prisms or octahedrons with pearly luster on the cleavage surface. It is a hydrous silicate of calcium and potassium.
from The Century Dictionary and Cyclopedia
- n. A mineral allied to the zeolites, occurring in laminated masses or in tetragonal crystals, and having a strong pearly luster on the surface of perfect cleavage, parallel to which it separates readily into thin laminæ.
Sorry, no etymologies found.
Acid calcium silicates are represented in the mineral kingdom by gyrolite, H_2Ca_2 (SiO_3) _3·H_2O, a lime zeolite, sometimes regarded as an altered form of apophyllite
And preserved inside a Victorian-style glass dome is a pearly lump of the mineral apophyllite, selected by Meitner as the closest solid representation of the unstable element