DESCRIPTION: A genuine vintage sterling silver blue john brooch. The gemstone is not a doublet or triplet, it's a whole piece of blue john. The item weighs approx. 6.05g and the size dimensions are in the later photos. It's hallmarked for sterling silver, dating to 1987. Blue john is an extremely rare mineral and can only be found in Derbyshire in the UK (not far from me), it is in fact Britain's rarest mineral.
