1493 has some explanations for this, i.e. silver, but mostly guano https://en.m.wikipedia.org/wiki/1493:_Uncovering_the_New_World_Columbus_Created https://en.m

1493 has some explanations for this, i.e. silver, but mostly guano https://en.m.wikipedia.org/wiki/1493:_Uncovering_the_New_World_Columbus_Created https://en.m.wikipedia.org/wiki/1493:_Uncovering_the_New_Wor...