Osmium Ice is considerd to be the hardest and coldest ice there is on earth with a melting point of 100 C meaning it takes a long time for this type of ice to even show a sign of melting in normal temperatures. This Ice have left scientists dumbfounded when it was discovered in may 6th 1995 in the depths of the north pole by Hernandez Cara a Glaciology. Not only does this ice have a high melting point, but it's also really dense (thus takes the name Osmium ice “osmium” being one of the densest materials on earth) meaning it's heavy and if a person touches this ice without protection then it starts to burn off your skin immediately. When scientists recovered this ice they had to use all types of machines to cut through this including a fiber and CO2 laser. Most of this ice was recovered from the depth of the glaciers in the north pole, but they speculate that more Osmium ice is hidden underneath the arctic ocean.
The temperature of this material is around -500 celsius making it extremely cold and the coldest ice there is. If you were to drop this ice in a room temperature bowl of water it will start to freeze the water around it and this exact behavior makes it really hard for scientists to obtain pure Osmium Ice since it's constantly freezing the surroundings and therefore sticks to things. Scientists have yet to figure out a use for this type of ice since it's really hard to maintain and handle, but regardless of that this ice goes for $15,000 per kilogram making it the most expensive ice out there.