Copper, silver, and gold have all been know since ancient times because they appear in nature and were thus discovered thousands of years ago. but the majority of and, consequently, are hard to find in nature.

elemental form,  readily form compounds

Explanation:

Copper, silver, and gold have all been know since ancient times because they appear in nature in_elemental form___ and were thus discovered thousands of years ago. But the majority of elements__readily form compounds_and, consequently, are hard to find in nature.

that tool would be a compass