Portal:Chemistry/Featured article/17

Diamond is the hardest known natural material (third-hardest known material after aggregated diamond nanorods and ultrahard fullerite), and is an allotrope of carbon. A diamond is a transparent crystal of tetrahedrally bonded carbon atoms. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Most notable are its extreme hardness of diamond, its high dispersion index, and high thermal conductivity.