Lapis armenus, also known as Armenian stone or lapis stellatus, in natural history, is a variety of precious stone, resembling lapis lazuli, except that it is softer, and instead of veins of pyrite, is intermixed with green. "The Armenian stone" is so similar to lapis lazuli that it has often not been distinguished from it; Webster's Revised Unabridged Dictionary for instance treats the two terms as synonyms. The Dictionary of Traded Goods and Commodities 1550-1820 defines lapis armenus as Chemically however lapis lazuli is not at all similar.