Crystal

A crystal is a solid material where atoms or molecules are arranged in a highly ordered, repeating pattern that extends in all directions, like a 3D puzzle where the same piece repeats over and over. This organized structure gives crystals their characteristic flat faces, sharp edges, and often beautiful geometric shapes, which is why gemstones like diamonds and quartz are naturally crystalline. Because of their orderly atomic arrangement, crystals have special properties that make them useful in everything from electronics and lasers to medicines and jewelry.