This is a Ben Zuckerman cocktail coat in the heaviest, richest green velvet. It is double breasted and has the classic Zuckerman jewelled buttons that make the coat out of the ordinary. I suspect this coat is made of silk velvet, which is simply silk woven into a velvet which leads to an incredibly soft and luxurious velvet, with a very high price tag. It is almost impossible to find 100% silk velvet today but it was used more frequently in the past.

Photos courtesy of Kleopatra's Kloset.