Each point conveys one gem (7)
I believe the answer is:
peridot
'gem' is the definition.
(I know that peridot is a type of transparent gem)
'each point conveys one' is the wordplay.
I cannot really understand how this works, but
'each' could be 'per' ('per' can mean for each) and 'per' is present in the answer.
'point' could be 'dot' (synonyms) and 'dot' is found in the answer.
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for peridot that I've seen before include "A green semi-precious stone" , "Top ride (anag) - gemstone" , "olivine" , "mineral" , "I deport (anag) - gemstone" .)