The seven notable fossil fuels are presented here in alphabetical order: coal, gas, gas hydrate, oil, oil sand, oil shale and peat. They are far from equal. Coal is preeminent, but it was not the first. Oil and gas, or petroleum, comes next in history and in importance to civilization. Oil sand and oil shale are minor today but poised for a greater role. Gas hydrate or methane hydrate (or methane ice) has greater promise than all of these, but is barely beginning to be produced. And peat, important in local regions, is the oldest of these in human use yet so young geologically that some do not consider it a fossil fuel at all.