What makes limestone a high grade or low grade?

Limestone is classified as high grade or low grade based on its purity and the presence of impurities. High-grade limestone contains a high percentage of calcium carbonate (CaCO3), typically over 95%, and has minimal impurities such as clay, silica, or iron oxides. In contrast, low-grade limestone contains a lower percentage of calcium carbonate and higher levels of impurities, which can affect its suitability for various industrial applications. The grade of limestone influences its uses in construction, agriculture, and manufacturing processes.