Question

Rank the following materials from least to greatest density: cast aluminum, cold-drawn steel, limestone, marble, packed gravel, and copper.

Answer

Ranked from least to greatest density:

1. Packed gravel: 110 pounds per cubic foot (1,762 kilograms per cubic meter)
2. Limestone: 135 pcf (2,162 kg/cu m)
3. Cast aluminum: 165 pcf (2,643 kg/cu m)
4. Marble: 173 pcf (2,771 kg/cu m)
5. Cold-drawn steel: 490 pcf (7,849 kg/cu m)
6. Copper: 556 pcf (8906 kg/cu m)

Gold, by the way, at 1,205 pcf (19,302 kg/cu m), is over twice as dense as steel.