Liddell-Scott-Jones

ἀδάμας (adamas) adamant ^G:N-M

ἀδάμας-ας, αντος, ὁ,

(δαμάω):—first in [Refs 8th c.BC+], properly, unconquerable:

__I substantive, adamant, i. e. the hardest metal, probably steel, χλωρός, πολιός, [ἀδάμαςαντος ἔχον κρατερόφρονα θυμόν “Op.” 147 ">Refs 8th c.BC+]; of anything fixed, unalterable, ἔπος ἐρέω ἀδάμαςαντι πελάσσας Oracle texts cited in [Refs 5th c.BC+]; ἀδάμαςαντος δῆσεν ἅλοις fixed them with nails of adamant, i. e. inevitably, [ἀδάμαςαντα 3rd c.BC: Theocritus Poeta Bucolicus 2.34. ">Refs 5th c.BC+]
__I.2 diamond, [Refs 5th c.BC+]
__I.3 metaphorically, ὁ πόνος ἀδ άμαντος, of love, [Refs 2nd c.AD+]
__II adjective, unbreakable, ἀνακτίτης[Refs 5th c.AD+]