I couldnt find any specific grade for Brazils Lamberti Bianco Quartzite. It is a natural stone product that varies in color, pattern, and quality depending on the quarry and region. However, it is a high-quality quartzite that is ideal for countertops, flooring, and walls. The final grade of Lamberti Bianco Quartzite depends on multiple factors such as color consistency, texture, thickness, and finish. It is recommended to discuss specific grading systems with a supplier or fabricator for more information.