In 1886, Charles Martin Hall developed an inexpensive process to extract this pure metal from its ore.
- Gold
- Platinum
- Aluminum
- Tungsten
In 1886, Charles Martin Hall developed an inexpensive process to extract this pure metal from its ore.
Aluminum. Until Hall’s discovery aluminum was more precious than gold. The French government displayed aluminum bars next to the crown jewels, and Napoleon III reserved a set of aluminum cutlery for special guests.