n. A white variety of olivine that is mostly magnesium silicate Mg2SiO4.
The Century Dictionary and Cyclopedia
n. A crystallized mineral which occurs at Vesuvius accompanied by pleonaste and pyroxene.
Word Usage
"It was the crew of Apollo 15 who first found green olivine - specifically, a magnesium-rich variety that goes by the name forsterite, which is also the kind that was spotted by Spitzer."