THE SPHRAGITIDES were the Oreiad or Naiad nymphs of a cavern oracle on Mount Kithairon (Cithaeron) in Attika (southern Greece). They were presumably named for the gemstones of the grotto.
SPHRAGI′TIDES (Sphragitides), a surname of a class of prophetic nymphs on mount Cithaeron in Boeotia, where they had a grotto called sphragidion. (Plut. Aristid. 9 ; Paus. ix. 3, in fin.; Plut. Sympos. i. 10.)
Source: Dictionary of Greek and Roman Biography and Mythology.
Pausanias, Description of Greece 9. 3. 9 (trans. Jones) (Greek travelogue C2nd A.D.) :
"About fifteen stades below the peak [of Mount Kithairon in Boiotia] is a cave of the Nymphai Kithaironides. It is named Sphragidion, and the story is that of old the Nymphai gave oracles in this place."
Plutarch, Life of Aristides 11. 3 (trans. Perrin) (Greek historian C1st to C2nd A.D.) :
"Aristides [an historical Athenian leader early C5th B.C.] sent to Delphoi and received from the god response that the Athenians would be superior to their foes if they made vows to Zeus, Hera Kithaironia (of Mount Kithairon), Pan, and the Nymphai Sphragitides . . . the cave of the Nymphai Sphragitides was on one of the peaks of Kithairon (Cithaeron), facing the summer sunsets; and in it there was also an oracle in former days, as they say, and many of the natives were possessed of the oracular power, and these were called nympholeptoi, or nymph-possessed."
- Pausanias, Description of Greece - Greek Travelogue C2nd A.D.
- Plutarch, Lives - Greek Historian C1st-2nd A.D.