Science, Tech, Math › Science Are Icebergs Made of Freshwater or Saltwater? Share Flipboard Email Print Michael Leggero/Getty images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated November 30, 2018 Icebergs form from a variety of processes, yet even though they may be found floating in salty seawater, they are primarily made of freshwater. Icebergs form as a result of two main processes, producing a freshwater iceberg: Ice that forms from freezing seawater typically freezes slowly enough that it forms crystalline water (ice), which does not have room for salt inclusions. These ice floes are not truly icebergs, but they can be extremely large chunks of ice. Ice floes typically result when the polar ice breaks up in the springtime.Icebergs are "calved," or form when a piece of a glacier or other land-based ice sheet breaks off. The glacier is made from compacted snow, which is freshwater.