I love when my mind is blown in class, especially in chemistry. Surprise! In the lecture before our Fall Break, my professor decided to show us what a supercritical liquid looks like since we were talking about phase changes and some of the math behind the different states.
A supercritical liquid is when matter is put under high temperature and pressure. For different substances there are different combinations to get this to happen. It shares the qualities of both a liquid and a gas. It spreads out like a gas, however, like a liquid can dissolve things, is very dense, and is viscous.
Below is a video of what that phase change looks like for CO2: