White Metal is any alloy that is light-colored, and is used especially as a base for plated silverware, ornaments and jewelry. Some of the metals used to create this alloy are antimony, tin, lead, cadmium, bismuth and zinc. Not all of these metals are found in all white metal alloys, but are combined to achieve a desired need, such as being able to be casted and polished.
Spinel is the magnesium aluminum member of the larger spinel group of minerals. Its hardness is 8, its specific gravity is 3.5–4.1, and it is transparent to opaque with a vitreous to dull luster. It may be colorless, but is usually various shades of red, blue, green, yellow, brown, or black.