Viridian

Chambers's Encyclopaedia, Volume 10: Swastika to Zyrianovsk and Index, p. 493

Viridian is a bluish-green pigment of much depth and purity. It is a hydrated sesquioxide of chromium, and is a valuable modern addition to the artist's palette. Neither light nor sulphuretted hydrogen gas has any action upon it, and it mixes with other colours without injuring them.

Source scan(s): p. 0520