Ruby / Corundum:
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.
Ruby / Corundum is a crystalline form of aluminum oxide (Al2O3) typically containing traces of iron, titanium, vanadium and chromium. It is one of the naturally transparent materials, but can have different colors when impurities are present. Transparent specimens are used as gems, ruby if red and padparadscha if pink-orange. All other colors are called sapphire, e.g., "green sapphire" for a green specimen. Because of corundum's hardness (pure corundum is defined to have 9.0 Mohs), it can scratch almost every other mineral.