A thrift store find

I recently picked these lamps up at a thrift store. I feel in love instantly and knew I had to have them. Each one is extremely heavy. The height of each lamp is about 3 ft. and the width across the top part comes to about 20 inches. I can't tell if the marble on the base is real and if the dangling crystals are anything special. I'm assuming the base is made out of brass, but I'm not an expert. 1972 is carved on the bottom with a symbol that I am not familiar with. Any information on these lamps would be greatly appreciated!