Yes, lab-grown diamonds will come with a certificate just like natural diamonds do. The two main grading labs that grade the stones we carry are IGI and GCAL. IGI is the larger grading house with labs all over the world. IGI is still improving its grading standards, and have been consistent for us. At our store, we pre-screen the diamonds before purchasing them for our inventory to make sure they are true to grade. GCAL is a slightly smaller grading house that is considered to be highly regarded and consistent.