Discovering the Birmingham Assay Office Gemmology Lab: A Gem Lover's Paradise
- Dimitri
- Apr 14, 2025
- 5 min read
Updated: 1 day ago
Last week, I had the opportunity to visit one of the coolest places in the UK gem world – the Birmingham Assay Office Gemmology Lab. This was actually my third time visiting, and each visit offers something new to learn.
A Rich History
The Birmingham Assay Office has a storied history, having been established in 1773. Although it's primarily known for hallmarking precious metals, its gemmology lab is much newer, dating back to 2000. This lab was set up specifically for gem testing, diamond grading, and providing specialized reports for the jewellery trade. The lab collaborates closely with SafeGuard to ensure every examined piece is accurately identified, assessed, and valued. Over the years, they have built a solid reputation for being reliable, precise, and high-tech.
Cutting-Edge Technology
Walking through the lab, it's fascinating to see just how advanced their technology is. They utilize specialized equipment such as DiamondSureâ„¢ and SYNTHDetect for identifying synthetic diamonds, the DiamondViewâ„¢ to reveal diamond growth patterns, as well as Raman and FTIR Spectrometers for gemstone identification and detecting treatments. Additionally, they employ the Sarine DiaMensionâ„¢ system for measuring diamond proportions. For pearls, dedicated X-ray machines help determine whether a pearl is natural, cultured, beaded, or non-beaded. It's truly impressive to witness all these tools in action, making the Birmingham Assay Office one of the best places in the UK for gem testing.
My Exciting Journey to Birmingham
My journey began early in the day. I boarded a direct train from Cardiff to Birmingham New Street. The trip only took about two hours, making it relatively easy. Once I arrived, I hopped into a taxi that took me straight to the Assay Office, located on Moreton Street in the Jewellery Quarters. The building itself is modern and sleek; upon entering, I knew I was somewhere extraordinary.
Testing My Pearls
My visit wasn't just for leisure; I brought along a strand of pearls and some gemstones for testing. The highly trained gemmologists greeted me warmly and guided me through the entire pearl testing process. Their expertise made it an exciting experience.
Pearl X-ray Magic
First, we conducted X-ray testing. They utilized an old Hewlett Packard 43805N X-ray system (definitely older than me!). Despite its age, it amazed me by revealing the internal structure of pearls.
Watching them work was like stepping into a time machine. They carefully placed my pearl strand on a special plate and applied X-rays. The most enjoyable part was developing the film by hand, merging the worlds of science and art.
Analyzing the Results
Once the film was ready, we examined each pearl closely with a loupe. This part was eye-opening as we checked if the pearls were beaded or non-beaded.
Beaded pearls contain a small bead inside, evident in an X-ray as a neat circle. In contrast, non-beaded pearls consist entirely of nacre, making them appear sturdy and more genuine.
Recognizing the differences is vital in determining a pearl's growth method and estimated value. This skill requires a sharp eye and significant experience.
Advanced Chemical Analysis
Following that, we conducted another X-ray test using a modern machine. This one analyzes the chemical composition of the pearls to identify if they are freshwater or saltwater.
The process was clever. Different types of pearls contain varying chemical elements. Freshwater pearls, typically grown in rivers and lakes, have elevated levels of manganese and lower levels of strontium. In contrast, saltwater pearls, like South Sea, Akoya, and Tahitian, show the reverse – higher strontium and a decrease in manganese. South Sea pearls exhibit particularly strong strontium signals due to their growth location.
By analyzing these microscopic traces, the lab can determine if a pearl is freshwater or saltwater. They can even gain insights into the pearl's geographical origin. It's astounding how much can be learned from tiny fragments of a pearl's structure!
Grading the Pearls
Once the testing is complete, the pearl strand moves on to the grading process. They employ the GIA’s 7 Pearl Value Factors: size, shape, color, luster, surface quality, nacre quality, and matching. This comprehensive evaluation produces a detailed report.
Understanding the Value Factors
Each of the GIA's 7 Pearl Value Factors provides important insight into the pearls:
Size: Larger pearls are generally rarer and more desirable. The lab measures each pearl meticulously to note its size.
Shape: While perfectly round pearls are the classic choice, many people appreciate other shapes like oval, drop, and baroque.
Color: Pearls can display a range of colors, from classic white to pink, gold, silver, and even peacock green. The lab evaluates both the body color and any overtone (the additional shimmer).
Luster: Luster relates to a pearl's shine. High-quality pearls have a sharp, bright reflection, almost like a mirror.
Surface Quality: The team examines the pearl's surface for cleanliness. Being a natural product, pearls may have minor marks, but fewer blemishes usually lead to a higher grade.
Nacre Quality: This focuses on the thickness and smoothness of the nacre (the layers of pearl material). Superior nacre provides strength and richness to the pearl.
Matching: For strands like mine, the matching process involves considering size, color, shape, and luster. Better-matched pearls contribute to a more beautiful overall strand.
Grading pearls requires meticulous attention to detail, and it's wonderful to witness the dedication and skill involved in the process. Every tiny factor matters!
Conclusion: A Memorable Experience
I left the Birmingham Assay Office completely amazed. Observing the pearls undergo testing, X-rays, chemical analysis, and grading felt like witnessing the union of science and art. Each step, from determining if a pearl is beaded or non-beaded to identifying whether it's freshwater or saltwater, showcases the incredible skill, dedication, and precision involved in pearl testing.
This visit was both enjoyable and insightful. A massive thank you to the remarkable gemmologists who took the time to guide me through the entire process.
To conclude the day, we took a group photo – a cherished memory from my third visit to this fantastic laboratory. If you get a chance to visit the Birmingham Assay Office Gemmology Lab, I can’t recommend it enough!
To learn more about The GIA 7 Pearl Value Factors visit the GIA's website HERE
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