Chinese made first use of diamond

The BBC has an article about how the chinese were using diamonds to polish rocks earlier than anyone else... What I want to point out is the lower picture which I have included.

Look at that shine after if I read it right 4500 years...

BBC NEWS | Science/Nature | Chinese made first use of diamond: "Harvard University physicist Peter Lu and colleagues studied four
ceremonial burial axes, the oldest of which dates to about 4,500 years
ago."