The origins of this word are unclear. According to Studer and Evans, turkemaus is a corruption of turkoise (from Latin turchesia), and was treated as such in the AND1. However, the stone is also mentioned in a continental version of Sydrac's lapidary as turquemaf/turquemaus and appears to have different characteristics and powers than the turkoise (as noted by William M. Holler, 'Unusual Stone Lore in the Thirteenth-Century Lapidary of Sydrac, Romance Notes, 20.1 (1979), pp. 135-42 (p.139). The word looks as if it may be considered a misreading of Anglo-Norman Turqueman, derived from Latin Turcomannus.