How much gold would a one km diameter iron asteroid contain?

Not very much actually, because Gold is a rare element. If you look at a Periodic Table Iron, Nickel, and Cobalt are in the middle of the 4th row. read more

A Million phones contain 35,274 lbs of copper, 772 lbs of silver, 75 lbs of gold, So a single phone contains around 0.03401942775 grams of gold Of course this varies a little from phone to phone. read more

How an asteroid could be captured and moved into a more convenient orbit. Credit Planetary Resources Asteroids contain an abundance of valuable resources including platinum, gold, iron, nickel, rare earth metals and water. read more