Aluminum is 0.05lbs. Buy on its own, or to complete your set with a previously purchased tungsten sphere. A great conversation piece. Includes certificate of chemical composition and interesting facts. Machined from precipitation-hardened aluminum alloy, this sphere is an excellent contemporary addition for your desk at work or side table at home. Now you can add one of nature's wonders to your own collection. If you like the sphere don't forget to check out our Tungsten and Aluminum Cube Sets.