An olive-green mineral called olivine is very frequently present.
"Geology"
James Geikie
The olivine tint is Hispano Moriscan-a complexion, if not more beautiful, certainly more picturesque than that of the Saxon blonde.
"The Lone Ranche"
Captain Mayne Reid
Thus trachyte is usually porphyritic; for in it, as in many modern lavas, there are crystals of feldspar; but in some porphyries the crystals are of augite, olivine, or other minerals.
"The Student's Elements of Geology"
Sir Charles Lyell