Black Diamonds

[Jonathan Saunders]

Reading through a mid-war letter the other day I came across the expression "black diamonds" and have no idea what it can mean. Has anyone come across this term/slang?

The context was a sailor aboard a dreadnought that had come into port after patrol (home port was Scapa but I guess it could be anywhere on north-eastern coast or western seaboard depending on where they had been patrolling). I dont have the quote at hand but he writes something along the lines of "several black diamonds have arrived". My initial thoughts were is this a Divisional sign but then why would troops be so far north? Another was whether it related to Empire troops? Finally was it a nickname for some ordnance such as a particular shell? There are no other clues I am afraid.

Any suggestions gratefully received.

[HERITAGE PLUS]

Signals

The term Black Diamonds was used in relation to a particular type of very pure, high quality coal that sparkled. Over time this became a term used for coal in general. The Black Diamonds could therefore be coalers with fuel to fill the coal-holds, particularly as the ship in question had just return from patrol.

Dave

[Jonathan Saunders]

Many thanks Heritage Plus. He refers to about 900 Black Diamonds coming aboard, which seems excessive although admittedly there would have been huge coal dumps needed to fuel the boilers. I am sure this is what he must have meant.

Many thanks again.

[Myrtle]

Signals

I have heard coal being called black diamonds by South Wales miners. Probably comes from both coal and diamonds being carbon based.

[Michael]

Jon

This probably refers to 900 tons of coal.

Mick

[Jonathan Saunders]

Thanks chaps. Curiosity satisfied.

I also have a copy of a letter from his brother (7 Duke of Wellingtons) and he refers to some "dark ladies" when he was billeted somewhere in Northumbria. I think his language was more literal than his RN brother!