Colonial Gemstones provides ethically sourced Colombian emeralds by Expert Sourcing, Independent Certification and Bespoke Services.
Every purchase is backed by documentation from world-renowned gemological laboratories such as GRS, Guild, Gubelin and SSEF, providing absolute confidence in the stone’s authenticity, treatments and origin.
When investing in a premium gemstone, the “paper” (the lab report) is as important as the stone itself. We primarily work with these three institutions because of their rigorous scientific standards.
Reputation: Known for "elite" or "museum-quality" stones. If a gemstone is being sold at a major auction house like Christie’s or Sotheby’s, it almost always carries a Gübelin report.
Specialty: They are world leaders in Origin Determination. Their scientists have a massive "reference collection" of stones from ancient mines, allowing them to confirm with extreme high-certainty if an emerald is truly from the Muzo or Chivor regions.
Best For: High-value investment emeralds (No Oil or minor enhancements) where provenance adds significant value.
Reputation: GRS is the industry standard for colored gemstones. They are credited with creating the trade terms that the market uses today, such as "Muzo Green" for the finest Colombian Emeralds.
Specialty: They excel at color grading and treatment identification. A GRS report that specifies "Muzo Green" is a powerful marketing tool that instantly communicates a stone's elite color profile to international buyers.
Best For: High-end commercial and "fine" jewelry stones. It is the most recognized lab among professional gemstone traders worldwide.
Reputation: Known for being highly specialized and technologically advanced. They have conducted extensive field research specifically in Colombian emerald mines.
Specialty: GUILD is highly respected for its Emerald Grading System. They use a very detailed classification for "Verdant Green" (their highest color grade for emeralds) and provide very clear, easy-to-read reports regarding oil levels and origin.
Best For: Clients looking for a balance of scientific accuracy and modern reporting. Their reports are often more visual and descriptive, making them excellent for retail consumers.
| Feature | Gübelin | GRS | GUILD |
| Origin | Switzerland (1923) | Switzerland (1996) | USA/Asia (1980) |
| Market Tier | Ultra-Luxury / Auction | Professional / High-End | Premium / Retail |
| Signature Term | “Old Mine” / Provenance | “Muzo Green” | “Verdant Green” |
| Key Strength | Scientific Heritage | Global Recognition | Specialized Emerald Data |
For Investment: We recommend Gübelin for stones of exceptional rarity.
For Global Resale: GRS is the most widely accepted “currency” in the gemstone trade.
For Detailed Analysis: GUILD offers incredible depth and specialized research into the specific mine of origin.
Note: At Colonial Gemstones, we ensure that the lab selected for your stone is the one that best validates its unique characteristics and protects your investment.
Download a PDF & Subscribe for occasional emails with important content, product updates and tips
By supplying your contact information, you authorize us to contact and promote our services to you on and across different services in accordance with our Privacy Policy.
Join an exclusive 10-day Emerald Tour into the heart of Colombia’s legendary emerald mines.
Exclusive Mine Access: Direct entry into active mining operations at Muzo & Chivor.
Technical Workshops: Hands-on training in grading, cutting and treatment identification.
Trading Mastery: Learn how the Colombian market operates from the inside.
Cultural Heritage: Professional guided city tours and historical insights into Bogotá.
Complete the details below to receive the full 10-day itinerary and professional pricing.
Limited spots available for 20th – 29th May 2026. This is an educational and cultural experience for true enthusiasts.