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 nearly identical 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. British History Online defines lapis armenus as "Armenian stone, or azurite, a naturally occurring basic copper carbonate, originally from Armenia, but later from Germany, from which blue bice was prepared. It was often found in association with another copper carbonate, malachite from which green bice was prepared... Probably because they were both blue, blue bice was sometimes misinterpreted to mean lapis lazuli." 
Herman Boerhaave believed it rather to rank among semi-metals, and supposed it was composed of both metal and earth. He added that it only differs from lazuli in degree of maturity, and that both of them seem to contain arsenic.
- This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed. (1728). "article name needed". Cyclopædia, or an Universal Dictionary of Arts and Sciences (first ed.). James and John Knapton, et al.
- Simply Crystals Jackson, p. 102
- George P. Merrill, Handbook and Descriptive Catalogue of the Collections of Gems and Precious Stones, p. 201, US National Museum Bull. 118, 1922
- 1998 Webster's
- Lapis armenus, citing Harley, R. D. (1970), Artists' Pigments, 1600-1835, London:Butterworths.
- Burton, Robert (1621). "SUBSECT. II.—Simples purging Melancholy downward". The Anatomy of Melancholy. Archived from the original on 7 November 2005. Retrieved 24 May 2006.
- Encyclopaedia Perthensis (1816). Encyclopaedia Perthensis; or, Universal dictionary of Knowledge; Supp. p. 526.