The densest “liquid” on earth is actually a metal: mercury. Mercury is not only awesome to look at and incredibly poisonous to ingest, but it is also more than 12 times more dense than water. It rates at 13.5 grams per cubic cm on the ol’ density scale, making it denser than many solid metals, including lead. Extra credit: In order to get mercury into a solid state, you have to chill it to right around negative 38 degrees Fahrenheit, which just so happens to also be negative 38 Celsius!
Basalt is the densest type of rock, with an average weight of more than three grams per cubic cm. Its weight and density ratio can vary based on the amount of other material, such as quartz, contained in a given sample, though in order to be considered actual igneous basalt stone, a given sample must be at least 80 percent pure lava rock. Some people might try to tell you diorite is denser, but just tell them to back off, turn around, and walk away.
3 Water Density
Water is at its most dense at 39 degrees Fahrenheit. Above that temperature, the space between water molecules is slightly expanded, and below 39 degrees, as water approaches the freezing point, it begins to grow slightly less dense again. The measureable difference in density is about .1 gram per centimeter cubed outside of this temperature sweet spot, but it is a definite difference. Now go win a bar bet.
2 Mumbai, India
The city with the greatest population density on our fair planet is, perhaps not that surprisingly, Mumbai, India. With a population of more than 14.3 million people living in around 230 square miles of area, there are around 60,000 people per mile squared. By comparison, there are fewer than 600,000 people living in the entire state of Wyoming, which has almost 100,000 square miles of area, for a population density of fewer than six people per square mile.
The densest naturally occurring element on the planet is osmium, a metal in the platinum family with a density of 22.6 grams per cubic centimeter. If that means nothing to you, then you’re normal. By comparison, lead is 11.3 grams per cm cubed. Osmium was distinctly isolated as an element in the early 1800s and, due to its brittle nature, is nearly useless for any practical purpose in its pure state. Oh well, it’s still nice and … dense.