I can't find very much information on Everledger's features process, just on the blockchain aspect, which doesn't inspire confidence. It's not enough for them to create 40 features you can fingerprint a diamond by, they have to be 40 features that are independently and consistently verifiable.

If I have to send my diamond to Everledger to verify it, I'm effectively just trusting them. Representing a physical object as a cryptographic hash for security doesn't work if the consumer can't independently verify the hash.