The stone archaeologists treat so cryptically (7)
I believe the answer is:
rosetta
'the stone' is the definition.
(I've seen this before)
'treat so cryptically' is the wordplay.
'cryptically' indicates anagramming the letters.
'treat'+'so'='treatso'
'treatso' is an anagram of 'ROSETTA'.
'archaeologists' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for rosetta that I've seen before include "Source of revelatory stone" , "somewhere in Egypt" , "The -- Stone is a famous British Museum exhibit" , "Famous stone's from here" , "Whence Champollion's stone" .)