No, diamonds are not just "iced carbon" in the same sense that ice is the solid form of water. The term "iced" implies that diamonds are formed through the freezing or solidification of carbon, similar to how water freezes to form ice. However, the formation of diamonds is quite different.
Diamonds are formed deep within the Earth's mantle under high pressure and temperature conditions. They are composed of carbon atoms arranged in a specific crystal lattice structure. This crystalline structure gives diamonds their unique properties, such as exceptional hardness and brilliance.
Unlike water freezing into ice, diamonds do not melt into liquid carbon under normal conditions. Instead, diamonds undergo a phase transition directly from a solid to a gas state through a process called sublimation. Under extremely high temperatures and in the absence of oxygen, diamonds can be converted directly to carbon vapor without passing through a liquid phase.
Regarding other solid elements, not all elements can be easily turned into gases or liquids. The ability of an element to exist as a gas or a liquid depends on its boiling point and sublimation point, which vary for different elements. Some elements have low boiling points and sublimate readily, transitioning directly from a solid to a gas, like carbon dioxide (CO2) or iodine (I2). Other elements have higher boiling points and require significant heat or pressure to convert them into liquids or gases.
There are a few elements that have extremely high melting or boiling points and are difficult to convert into gases or liquids under ordinary conditions. Examples of such elements include carbon (as diamond), tungsten, and osmium, among others. These elements have melting or boiling points well above typical atmospheric temperatures and pressures, making their conversion into liquids or gases highly challenging.