| To the eye, tumbaga plates would have had the appearance of pure gold. |
| Because it is an alloy of gold and copper, tumbaga is lighter than gold. |
| Many Spanish conquerors were fooled by depletion gilded tumbaga, believing it to be gold. |
| Many of the coppery-colored tumbaga castings were then gilded and burnished to restore their golden appearance. |
| There is evidence suggesting the transfer of tumbaga took place, and at a later date possibly brass technology. |
| On heating tumbaga in air, a layer of copper oxide forms on the surface of the object. |
