How much does petrified wood weigh?
OK, first, we’ve have to decide how large the piece of petrified wood is, because like anything else (cars, a sack of potatoes, kids) a big one will weigh more than a little one. To help get around this question of having to ask the size of the rock (or whatever) each time, scientists use a measurement called specific gravity, that allows us to compare different materials. To choose a few materials for comparison, water has a specific gravity of 1.0. Petrified wood (usually composed of the mineral quartz) would have a specific gravity of 2.65, so it is a little more than 2 1/2 times the weight of an equal amount of water. Gold has a specific gravity of 19.3. To make this a little more useful, imagine that you have a plastic container the size of a common brick (2 1/4 inches x 4 inches x 8 inches) and fill it with water. It would weigh a little more than 2 1/2 pounds. A piece of petrified wood the size of the brick would weigh nearly 7 pounds. And a gold brick would weigh about 50 pound