I had to look this one up. Says Wikipedia, "The mineral olivine (when of gem quality, it is also called peridot and chrysolite) is a magnesium iron silicate with the formula (Mg+2, Fe+2)2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface."

"Mg-rich olivine has also been discovered in meteorites,[11] the Moon, Mars,[12] in the dust of comet Wild 2, within the core of comet Tempel 1,[13] falling into infant stars,[14] as well as on asteroid 25143 Itokawa.[15] Such meteorites include chondrites, collections of debris from the early solar system; and pallasites, mixes of iron-nickel and olivine."

So now you know. Olivine also occurs as a place name and, I see, as a line of perfume. It gets around, it does.

It's also very pretty in pure form with its translucent green. It adorned the high priest's robe in ancient Israel. The apostle John sees it as the seventh foundation of the new Jerusalem, "coming down out of heaven from God, prepared as a bride beautifully dressed for her husband." It's fitting that her foundations should be gemstones.

I learn something new every day. Today it was green and beautiful. Thanks be to God.

The tree was green and beautiful, too, even when photographed with black and white film.

Argus C3 Brick, 35mm, yellow filter
Ilford Delta 400 Professional
Negative scan worked up in the Gimp