sand, used by Hom. for ψάμαθος only in Od. 12.243, later very freq., Hdt. 8.71, etc.: pl., grains of sand, αἱ ἀπʼ ἀλλήλων ἐσκεδασμέναι ψάμμοι S.E. P. 1.130: prov., ψάμμος ἀριθμὸν περιπέφευγεν Pi. O. 2.98; οἶδα δʼ ἐγὼ ψάμμου τʼ ἀριθμόν Orac. ap. Hdt. 1.47; ἐκ ψάμμου σχοινίον πλέκειν, of labour in vain, Aristid. 2.309J.; of something worthless, LXX Wi. 7.9, D.Chr. 77/8.30; ψάμμου ἄξιον Oenom. ap. Eus. PE 5.21.
metallic ore used by alchemists, in pl., Olymp.Alch. p.106B., Zos.Alch. p.239 B.
ἡ ψ. the sandy desert of Libya, the sand, Hdt. 3.25, 4.173; πλείστης ψάμμου OGI 666.27 (Egypt, i A. D.). (Prob. *ψαφ-μος, cf. ψαφαρός, ψῆφος, Lat. sabulum.)