Talk about hefty diamonds, there's also some famous hefty pearls. Pearls are also weighed by "carat" measurement these days to add to the carat confusion.
Take the Hope Pearl which is arguably the largest saltwater pearl ever found. It weighs an astonishing 450 carats! It is a white, drop shaped pearl, and comes from a large gem collection of Henry Philip Hope, none other than the London banker who also at one time owned the famous Hope Diamond.
http://www.dpe.ae/
Pearl Girl
Rating
Hefty Diamond Rings by: Yvonne
the heaviness or weight of a piece is called - "heft". If you are a collector, you should always be aware of this the moment you pick up a piece of jewelry, including finger rings. I use a digital pocket scale by neva which wasn't expensive and it weighs: g, oz, ct and gn. It has proven itself to be a very handy tool for jewelry detective work.
although you do mention the ring is very heavy with a big diamond, well if we interpreted the 14ct as in carat diamond weight it's still not going to come close to the best known of Richard Burton's purchases - the whopper 69.42-carat pear-shape, later to be called the Taylor-Burton Diamond!
So, not being carat as in diamond weight :-) most likely 14 ct mark will be the gold composition - 14 carat gold. There are lots of strange and deceptive markings for gold plating around. Apparently, among the Arabic countries they use the word translated from Arabic - "Chinese Gold" for gold plated items, which isn't very diplomatic, especially if you happen to be Chinese!
However, if the jeweler has tested the stone and it is in fact a girl's best friend , do a little dance, thanking the powers that be at the car boot! It's also unlikely the ring would be plated in this case. Diamonds and gold plating don't like each other. Not sure about the a letter, could be design number, manufacturing number etc..