I do not have information on the grading system for Brazilian Jade Quartzite as it can vary from supplier to supplier. However, in general, quartzite is categorized into different grades based on the quality of the stone, such as color, pattern, durability, and thickness. It is an important consideration in choosing the right type of quartzite for specific projects, such as kitchen countertops, wall cladding, or flooring. It is recommended to consult with a reputable supplier or a professional stone fabricator to determine the grade of Brazilian Jade Quartzite that meets your requirements.