Final answer:
The bond found in diamond that holds the carbon atoms together is the covalent bond, forming a strong and stable tetrahedral structure throughout the three-dimensional crystal.
Step-by-step explanation:
The type of bond responsible for holding atoms together in a diamond is the covalent bond, not a bond between a metal and a nonmetal (which would be an ionic bond). Diamonds are composed of carbon atoms bonded to each other in a tetrahedral geometry to form a three-dimensional network. This three-dimensional network extends throughout the diamond, making it one of the hardest known natural substances and giving it a very high melting point of approximately 4400°C. The carbon-carbon covalent bonds are very strong because they involve the sharing of electrons between nonmetal atoms. Each carbon atom contributes one electron to the bond, creating a stable group of electrons that orbits the positive nuclei of both atoms. These covalent bonds are single bonds using sp³ hybridization which forms a tetrahedral structure where each carbon atom is bonded to four others.