If you’re shopping for a diamond online, you’ll see letters like GIA, IGI, or EGL on listings. Those letters matter because they tell you who graded the diamond.
Think of a diamond “certificate” like a report card. It doesn’t make the diamond better—it just tells you what the diamond really is: its cut, color, clarity, and carat weight (the “4Cs”).
What GIA Means
GIA (Gemological Institute of America) is the lab most people consider the “strict teacher.” GIA is known for using very consistent standards and for being widely trusted in the diamond industry. Their reports focus on careful, unbiased grading of the 4Cs.
You can also verify a GIA report number online using GIA’s Report Check, which helps confirm the report matches what GIA has on file.
Simple take: If a diamond has a GIA report, many buyers feel extra confident.
What IGI Means
IGI (International Gemological Institute) is also a major lab. IGI is especially common for lab-grown diamonds and provides detailed reports that still cover the 4Cs and identify whether a stone is natural or lab-grown.
IGI also lets you verify your report online, which is a smart step when buying.
Simple take: IGI is very common (especially for lab-grown), and verification is easy—just check the report number.
What EGL Means
EGL is where you want to be more careful. “EGL” can refer to different branches (like EGL USA vs EGL International historically), and the market has long debated consistency between them. Some sources note that certain EGL reports have been perceived as less strict on color/clarity compared to labs like GIA.
Simple take: EGL doesn’t automatically mean “bad,” but it can mean you should double-check value and grading with a trusted jeweler before you buy.
At DW Gem Services, our professional gemologist brings years of hands-on experience evaluating diamonds and grading reports. We help you navigate certifications like GIA, IGI, and EGL, explain what those grades truly mean, and ensure you understand the real quality and value of the diamond you’re considering — before you buy.