It's impossible to answer this question without more context. "Usable amount" is very subjective and depends on what you want to use the metallic elements for.

To give you a better answer, please tell me:

* What are you looking for? Do you want to know what materials contain a lot of metallic elements? Are you interested in specific applications for these materials?

* What do you mean by "usable"? Do you need a large amount of metal? Are you looking for specific properties like strength or conductivity?

For example, here are some possibilities depending on what you're looking for:

* Ores: These are rocks and minerals that contain enough of a specific metallic element to be economically extracted. Examples include iron ore, bauxite (aluminum ore), and copper ore.

* Alloys: These are mixtures of metals that are designed to have specific properties. For example, steel is an alloy of iron and carbon, brass is an alloy of copper and zinc, and bronze is an alloy of copper and tin.

* Metals in everyday objects: Many everyday objects are made of metals, including cars, appliances, jewelry, tools, and even coins.

Please provide more information so I can give you a more specific answer.