Enamel composition by mass includes which of the following?

• A. 96% mineral, 1% organics, 3% water
• B. 80% mineral, 10% organics, 10% water
• C. 50% mineral, 25% organics, 25% water
• D. 60% mineral, 20% organics, 20% water

Answer: (A)

Enamel is extremely mineral-rich, and its mass is dominated by inorganic material. About 96% of enamel’s weight is mineral, mainly hydroxyapatite crystals. A small amount remains as organic matrix, around 1%, consisting of non‑collagenous enamel proteins, with roughly 3% being water. This combination gives enamel its exceptional hardness while keeping the organic content and water content very low. The other distributions that raise the organic or water fractions don’t align with enamel’s actual makeup, which is why the 96% mineral, 1% organic, 3% water composition is the correct representation.