Choose the word which is different from the rest.

Garnet
Ruby
Graphite
Emerald E. Topaz

The answer is C. Graphite.

Garnet, ruby, emerald, and topaz are all gemstones. Graphite is a mineral.

Garnet is a hard, red, brown, or green mineral that is often used in jewelry. Ruby is a hard, red gemstone that is a variety of corundum. Emerald is a hard, green gemstone that is a variety of beryl. Topaz is a hard, blue, yellow, or pink gemstone that is a variety of aluminum silicate.

Graphite is a soft, black mineral that is used in pencils and lubricants. It is also a form of carbon.