Copper pure 78g, Michigan USA

Copper is relatively rare in the earth's crust. Its content is estimated to be 55-70 ppm (mg/kg). In seawater, its concentration varies only at the level of 0.003 milligrams in one liter. It is believed that there are approximately 1 billion hydrogen atoms for each copper atom in the universe. Pure copper is found in nature, but rarely in large quantities and is therefore found mainly in compounds. Elemental is found to a greater extent near Lake Superior in North America. It is most often found in the form of sulfides.