From the Arabic for "hunting horn", it's another name for mother-of-pearl
... the technical name for mother-of-pearl ... from Italian naccaro (now 
nacchera), possibly from Arabic naqur "hunting horn" (from nakara "to hollow out"
),... [DOC] [TLE] Balashon - Hebrew Language Detective: yakar and makor [PAR] May 16, 2016 ...