Vintage 1979 Diamond 9ct Yellow Gold Tie PinVintage 1970s 9ct yellow gold necklace featuring a single diamond set into two circles. This piece was converted from a tie pin into a pendant by our expert Hatton Garden London goldsmith. ERA Vintage, 1970s HALLMARKS The piece has a number of hallmarks indicating it was made by in Birmingham, England in 1979 from 9ct yellow gold by 'ML'. The pendant is not hallmarked, the following hallmarks were originally on the pin of the tie pin ML, Crown, 375,