Art Effects Manufacturing Co. Offers Onyx Marble Finish Cremation Urn. Art Effects Manufacturing Co. Is into production of metal cremation urns and the company has gained ISO 9001:2000 Certification. This Onyx Marble Finish Classic Alloy Cremation Urn is an adult and has solid [alloy] aluminum onyx marble finish. The urn requires no maintenance. It comes with a threaded "screw-on" top lid and felt bottom.