Examples of this include some plastics and some glass. Now, we should also mention that there is another type of solid or another type of formations that solid solids form. And this is called polymers. Now, we can have both polymers of amorphous solids and polymers of crystalline solids. Now, when we melt polymer solids very quickly, we get amorphous solids. When we melt polymers very slowly over a very long range of time, we get crystalline solids.