You do not need to have an Elizabethan vocabulary or know that carret is a double pun on the royal hair colour and jewels. You only need to know that Spenser comes from an more ancient, stoic tradtion.
He is to be pitied, for love is not a God.
It is poison.
In nature, apt to like, when I did see
Beauties which were of many carrets fine,
My boiling sprites did thither then incline,
And, Loue, I thought that I was full of thee:
But finding not those restlesse flames in mee,
Which others said did make their souls to pine,
I thought those babes of some pinnes hurt did whine,
By my soul iudging what Loues paine might be.
But while I thus with this young lion plaid,
Mine eyes (shall I say curst or blest?) beheld
Stella: now she is nam’d, neede more be said?
In her sight I a lesson new haue speld.
I now haue learnd loue right, and learnd euen so
As they that being poysond poyson know.
Sir Philip Sydney