The goal of placing countertop stone in classes is to help one with budget & comparisons.
For example, based on layout and other details, one can get a quote for a couple of stone classes to help set a budget. If one then determines that a Natural Class C fits the budget, as the project moves forward, one would then be able to choose a Natural Class A, B or C, knowing it fits the budget.
In addition, if one likes two different stone options equally, but they fall in different classes, the class may then help them choose.
The class of the stone or quartz, depends on several factors which may include.
Rarity of the Stone / Availibility Location of Stone Deposit Transportation Factors & Cost Fabrication Work Ability Demand Storage Factors Stone Integrity
Within a specific stone name, one can get differences in class between stone blocks & bundles. For example, an extra nice block of Blue Flower granite, could demand a high Class then the same stone with less blue.