Wulfenite is a secondary mineral of lead. and is a lead molybdate with the formula of PbMoO4 Wulfenite can be a vibrant colour of orange, but can also be very variable in colour, ranging from orange to yellow and brown. This specimen is coloured a dull orange, bordering on brown. The crystals are tabular with a rectangular shape and for the most part are intersecting each other. Unfortunately the origin of the specimen is not known, but is in my collection as a "type" specimen.