When is a $300 Black Diamond ring going to be worth $400?

The price of a $200 diamond ring has jumped more than $400 in the past 24 hours on a global black diamond market, according to a tweet from one user. 

The tweet, which was retweeted by someone named @mattwong, said: “$300 diamond ring is worth $450.

$300 black diamond ring was priced $150 last night.

$400 black diamond rose by $30 to $450 today.”

The tweet has since been deleted, but it was reported by Bloomberg that the price of the diamond rose from $450 to $400 over the past day.

Black Diamond rose by nearly $30 on Tuesday to $500, up from $350 on Monday.

Black Diamond rings have long been a luxury item, and many have a gold finish.