Γαγάτης
From LSJ
οὗτος μὲν ὁ πιθανώτερος τῶν λόγων εἴρηται, δεῖ δὲ καὶ τὸν ἧσσον πιθανόν, ἐπεί γε δὴ λέγεται, ῥηθῆναι → this is the most credible of the stories told; but I must relate the less credible tale also, since they tell it
English (LSJ)
(sc. λίθος), ου, ὁ,
A lignite, Orph.L.474, Plin.HN36.141, Dsc.5.128, Gal.12.203, Gp.15.1.32. 2 jet, Solin.22.11. II = ἀστράγαλος, cj. in Ps.-Dsc.4.61. (From Γάγας or Γάγγαι, a town and river in Lycia.)