Magnesium Iron Silicate is Olivine. It has a very distinctive olive-green color: https://en.wikipedia.org/wiki/Olivine.
Cummingtonite is Magnesium Iron Silicate Hydroxide. It's not a plausible eye-color: https://en.wikipedia.org/wiki/Cummingtonite.
I guess it's possible they were making this joke and flubbed it by leaving out a word?
(I looked it up because I live near Cummington MA, which it's named after)
Magnesium Iron Silicate is Olivine. It has a very distinctive olive-green color: https://en.wikipedia.org/wiki/Olivine.
Cummingtonite is Magnesium Iron Silicate Hydroxide. It's not a plausible eye-color: https://en.wikipedia.org/wiki/Cummingtonite.
I guess it's possible they were making this joke and flubbed it by leaving out a word?
(I looked it up because I live near Cummington MA, which it's named after)