On growing new markets which was used to stabilize the price in the past:

The last remaining global market would be Africa, where ­diamonds have “too bad a reputation”, Ogden said. “I’m not sure they’ll be convinced that buying diamonds is good.”

Hmm, I wonder why that might be…

Diamonds are a complete scam and always were. The mining industry behind it is abusive to boot. The sooner they crash the better