Lewis & Short

2. crēta, ae, f. [orig. adj., from 1. Creta], Cretan earth, i. e. chalk, white earth or clay.

  1. I. Prop., Plin. 35, 17, 57, § 195 sq.; Cato, R. R. 39, 2; Varr. R. R. 1, 7, 8 al.; esp. used for cleansing garments, Plaut. Aul. 4, 9, 6.
    Hence, trop.: creta est profecto horum hominum oratio, i. e. removes all trouble from the mind, Plaut. Poen. 5, 2, 10 sq.
    Also used as a cosmetic, Hor. Epod. 12, 10; Mart. 6, 93, 9; 8, 33, 17 al.; for seals, Cic. Fl. 16, 37; cf. cretula, for marking the goal in a race-course, Plin. 8, 42, 65, § 160; for the making of earthen vessels, Col. 3, 11, 9; Plin. 14, 20, 25, § 123 et saep.
    Poet.: rapidus cretae Oaxes, turbulent, Verg. E. 1, 66 Rib. (dub. al. Cretae; v. Forbig. ad loc.).
  2. II. From its whiteness is borrowed the trope for something favorable or lucky (opp. carbo), Hor. S. 2, 3, 246; imitated by Pers. 5, 108.