Certification for colored gemstones serves a different purpose than diamond certification. A diamond report assigns precise grades for cut, color, and clarity. A colored stone report focuses on identification (is this really a ruby?), treatment disclosure (has it been heated?), and origin determination (where was it mined?).
For valuable colored gemstones — especially those over $1,000 — an independent lab report is essential. It protects your investment and provides documentation for insurance and resale.
Major Gemstone Certification Labs
| Feature |
GIA |
GRS |
Gübelin |
SSEF |
AGL |
IGI |
| Full Name | Gemological Institute of America | Gem Research Swisslab | Gübelin Gem Lab | Swiss Gemmological Institute | American Gemological Laboratories | International Gemological Institute |
| Headquarters | Carlsbad, CA | Hong Kong / Switzerland | Lucerne, Switzerland | Basel, Switzerland | New York, NY | Antwerp, Belgium |
| Best Known For | Global authority; widest recognition | Color descriptors (Pigeon Blood, Royal Blue) | Origin determination | High-value stone analysis | US market colored stones | Diamonds; growing in gemstones |
| Origin Reports | Yes | Yes (detailed) | Yes (pioneered it) | Yes | Yes | Yes |
| Treatment Disclosure | Yes | Yes | Yes | Yes | Yes | Yes |
| Color Descriptors | Basic (Blue, Red, Green) | Proprietary (Pigeon Blood, Royal Blue, Vivid) | Descriptive | Descriptive | Descriptive | Basic |
| Clarity Grade | No | No | No | No | No | No |
| Auction Accepted | Yes | Yes | Yes | Yes | Yes (US) | Varies |
What Is on a Colored Stone Report?
A typical colored gemstone report includes:
- Identification: Confirms the stone is a natural ruby, sapphire, emerald, etc. This is the most fundamental purpose — verifying that your "ruby" isn't a garnet or synthetic.
- Weight: Precise carat weight, measured to the hundredth of a carat.
- Measurements: Length × width × depth in millimeters.
- Shape and Cut: The outline (oval, cushion, emerald) and cutting style (brilliant, step, mixed).
- Color Description: A written description of the stone's color. GRS uses proprietary terms like "Pigeon Blood" and "Royal Blue" for exceptional colors.
- Treatment: Discloses any treatments — heated, unheated, oiled, filled, irradiated, etc. This is critical for value.
- Origin: Geographic source when determinable. Labs use microscopic inclusion analysis and spectroscopic data to identify origin.
What Is NOT on a Colored Stone Report?
Important: Unlike diamond reports, most colored gemstone reports do NOT include:
- Clarity grade — No IF, VVS, VS, SI, or EC designation. The clarity terms used in the trade (and on our product pages) are dealer assessments, not lab grades.
- Cut grade — No Excellent, Very Good, Good rating. Colored stone cutting is evaluated subjectively.
- Color grade — No standardized letter or number scale. Color is described in words, not codes.
This means that when you see a clarity grade like "EC" on a product listing, it is the seller's assessment based on visual inspection — not a lab-assigned grade. Reputable dealers use these terms consistently and honestly, but they are not standardized the way diamond grades are.
When Does Certification Matter?
- Always for rubies, sapphires, and emeralds over $500. These are the "Big Three" and the most commonly treated and imitated gemstones.
- Always for untreated stones. An untreated ruby can be worth 5-10× more than a heated one. Without a lab report confirming "no treatment," you have no proof.
- Always for origin claims. "Kashmir sapphire" or "Burmese ruby" commands a massive premium, but origin can only be verified by a qualified laboratory.
- For any stone over $1,000. The cost of a lab report ($50-$300) is trivial compared to the value it protects.
- For insurance. Most insurers require an independent report to issue coverage on high-value gemstones.