China Blue Limestone is typically available in various grades, including First Grade, Second Grade, and Commercial Grade. The grade of China Blue Limestone refers to the quality, appearance, and durability of the stone. The First Grade China Blue Limestone is considered to be of the highest quality, with the most consistent color, minimal imperfections, and good durability. Second Grade and Commercial Grade may have more variations in color, more imperfections, or lower durability. It is important to note that the grading can vary between suppliers, so it is recommended to check with the specific supplier for their classification of China Blue Limestone.