Independent Gemological Laboratory · Est. 1980
Jewelry & Gemstone Appraisals in Downtown Chicago
More than a value. A permanent record of what you own.
A jewelry appraisal establishes the identity, quality, condition, and replacement value of your piece - giving you reliable documentation when it matters most.
Established in 1980 - over 45 years of independepnt grading
★★★★★ 4.8 rating on Google
Same-day service by appointment
The appraisals we issue
Every report includes an assessment of quality and discloses any treatment or enhancement. An appraised value can be issued to any report — please request it before the examination begins rather than afterwards.
Our signature gemological report that documents a jewelry piece or gemstone’s key quality characteristics, treatments; including photograph and appraisal value.
Ideally suited for single pieces of jewelry being appraised for insurance or liquidation purposes.
Premier report for exceptional gemstones and jewelry, Jewelry Report of Quality provides an authoritative evaluation of quality, characteristics, and appraisal value. Includes premium photographing.
An independent opinion has a value of its own
For decades, our gemologists have evaluated diamonds, gemstones, and jewelry for clients around the world. GIA-trained and backed by experience grading and identifying millions of pieces, our team brings a depth of knowledge recognized and trusted by insurers, attorneys, jewelers, appraisers, and fellow experts throughout the industry.
Every appraisal reflects the same strict standards, technical precision, and experienced opinion that have established PGS Laboratory as a respected authority in the field.
★★★★★
"I purchased a diamond that was misrepresented by the seller. PGS conducted their analysis and determined it was inferior. PGS was instrumental in helping me get a refund from the seller with their assessment."
Fernando Castilla · Google review
★★★★★
"I had three pieces of my mum's jewelry appraised by PGS, and I couldn't be happier with the experience. The appraisal process was fast, courteous, and very affordable. The communication was extraordinary from start to finish, keeping me informed every step of the way.
Myriam was fantastic—professional, knowledgeable, and incredibly helpful throughout the entire process. I highly recommend PGS to anyone looking for reliable, efficient, and customer-focused jewelry appraisal services."
★★★★★
David Navon
The IDJ Corporation
"We've had a relationship with PGS for over 30 years. Their gemmological knowledge as well as their service has and continues to be excellent. We consider them a valuable resource for our industry."
★★★★★
"She walked me through the results and explained all the technical terms so I understood."
★★★★★
Palmer Abbey
"I cannot recommend Myriam highly enough. Her knowledge, expertise, and thoughtful guidance provided me with invaluable insight into a cherished family heirloom. From the very first conversation, it was clear that she brings an exceptional level of skill and integrity to her work. Myriam took the time to explain every detail with care and clarity, ensuring I truly understood the piece and its significance. She is honest, kind, and dedicated to her craft — qualities that are rare and deeply reassuring when it comes to jewelry appraisal & white-glove facilitation to GIA. I wouldn’t trust anyone else as much as her, and I’m grateful for the confidence and peace of mind she provided. Downtown Chicago is fortunate to have such a talented and principled professional."
Meet the Appraisers
The gemologists who founded PGS in 1980 remain personally involved at the microscope today. With decades of hands-on experience evaluating exceptional diamonds, gemstones, and jewelry, every appraisal benefits from the judgment of seasoned experts - not a rotating team of anonymous graders.
A pioneer in diamond and gemstone color nomenclature, published across peer-reviewed industry journals, and an expert diamond grader with more than 40 years of experience behind the microscope.
Former president of the Midwest chapter of the Women's Jewelry Association, and the person our clients name most often when they describe being walked through their results.
Estate and on-site appraisals
Some collections shouldn't travel. We can be engaged to carry out appraisals on site — at a residence, a bank, an attorney's office or an estate — bringing the laboratory to the collection rather than the other way around.
This is confidential work and we treat it accordingly. If you are an executor, an attorney, or an advisor with a collection that needs valuing, call us to discuss scope and scheduling.
Work we have been retained for:
Estate appraisals for prominent figures in the sports and entertainment industries
Evaluation of fine jewelry, watches, diamonds and gemstones for the Federal Bureau of Investigation
Evaluation for the United States Secret Service
Expert assessment in sensitive legal matters
What to expect
1
Book, or walk in
Same-day service is available by appointment. We also accommodate walk-in clients Monday to Thursday. We're on the third floor of the Mallers Building on South Wabash.
2
We examine the piece
Diamonds are color-graded against master comparison stones, and clarity is assessed under a corrected 10× loupe and microscope. Treatments and enhancements are identified and disclosed.
3
We explain the result
You leave with the signed report and an understanding of what it says — what the stone is, how it was graded, and how the value was arrived at.
Timing. A single-item appraisal takes a minimum of two hours. Same-day service is available by appointment, and the last same-day appointment is 1:00pm. Multiple items take 24 hours — if the work cannot be completed the same day, your pieces are held overnight in our safe.
Common questions
What's the difference between a report and an appraisal?
A report is a gemological document describing what the stone is. An appraisal adds a monetary value, arrived at by evaluating quality first and then valuing it for a specific purpose. Most clients want both, and we issue them together.
How long does an appraisal take?
A single item takes a minimum of two hours. Multiple items take 24 hours — if we can't finish the same day, your pieces are held overnight in our safe.
Can I get it done the same day?
Yes, by appointment. The last appointment we can accept for same-day service is 1:00pm. A same-day surcharge applies.
Do I need an appointment?
It is not necessary but it is recommended. We have a lot of clients waiting for their reports and can more easily accomodate you with an appointment.
Can you tell if a stone is lab-grown or treated?
Yes. Identifying synthetics, treatments and enhancements is core laboratory work, and every report discloses what we find.
Do you appraise watches?
Yes. Fine watches are verified and appraised just as a piece of jewelry should be.
My piece is a family heirloom. Is that a problem?
Not at all — a great deal of what comes across our table is inherited. Anything held overnight is secured in our safe.
Come and see us
We're in the Mallers Building in the Loop, a minute from the Washington/Wabash and Monroe stops.
Address
5 South Wabash Avenue, Suite 315
Third floor, Mallers Building
Chicago, IL 60603
Telephone
Hours
Monday – Thursday: 9:30am – 5:00pm CST
Friday – Saturday: by appointment
Last same-day appointment: 1:00pm