The question of whether a diamond is a porous stone stems from a misunderstanding about how gemstones are formed and maintained. The simple, scientific answer is that diamonds are not porous materials. This misconception arises because many other natural and synthetic gemstones exhibit some degree of porosity. This difference in internal structure sets the diamond apart from materials that can absorb liquids or chemicals.
What Porosity Means
Porosity is a physical property describing the amount of empty space, or voids, within a material. It is measured as the ratio of the volume of these voids to the total volume of the substance. A material is considered porous if it contains microscopic gaps or interconnected channels that can absorb and trap foreign substances like water, oils, or cleaning fluids. Highly porous materials include kitchen sponges or natural rock like sandstone. For many gemstones, these internal voids absorb body oils or soap residue, which can eventually discolor the stone.
The Crystal Structure of Diamond
The non-porous nature of a diamond is directly attributable to its unique and tightly bonded crystal structure. A diamond is composed solely of pure carbon atoms arranged in a dense, repeating pattern known as the diamond cubic lattice. Each carbon atom is strongly connected to four neighboring carbon atoms through covalent bonds, forming an extremely rigid, three-dimensional tetrahedral network.
This uniform and strong bonding leaves virtually no interstitial space or voids for foreign molecules to infiltrate. The resulting structure is one of the densest and hardest materials found in nature, rating a 10 on the Mohs scale of hardness. This lack of internal gaps prevents the absorption of liquids and chemicals, defining the diamond as non-porous.
Instances of “porous diamond” usually involve synthetic materials or rare impact diamonds. These may have a porous surface microstructure due to extreme geological processes or etching, which is distinct from the internal porosity found in softer stones.
How Non-Porous Materials Are Cleaned
The diamond’s non-porous nature has practical implications for its care, making cleaning relatively simple compared to porous stones. Since foreign substances cannot penetrate the stone, dirt, oil, and grime only adhere to the outer surface. The goal of cleaning is simply to remove this surface layer of contamination.
Standard cleaning methods involve soaking the diamond in a mild degreasing solution, such as warm water with a few drops of dish soap. Ultrasonic cleaners are also effective, as they use high-frequency sound waves to create microscopic bubbles that lift debris from the surface.
The stability of the diamond means it is invulnerable to virtually all common acids and chemicals. However, care must be taken to ensure the cleaning agent does not damage the surrounding metal setting.