The international gemological community has lost one of its great educators, researchers, and pioneers with the passing of Professor Mimi Ou Yang Chiu Mei, founder of the Hong Kong Gems Laboratory (HKGL), founder of the Hong Kong Institute of Gemmology (HKIG), internationally recognized Fei Cui jade researcher, and one of the most influential figures in modern jade studies.

Known throughout the industry as “The Jade Lady” and the “Queen of Fei Cui,” Professor Mimi devoted more than six decades to the study, teaching, and promotion of jade. Her work transformed not only the understanding of Fei Cui, but also the way the international gem trade evaluates, identifies, and discloses treated jade today.

Cath Hill, Chief Executive Officer of Gem-A, wrote:
“She was a passionate proponent of gemmological education and champion of Gem-A for many years. In 1987, hers was the first academic centre to teach Gem-A’s gemmology and diamond diploma courses in Chinese paving the way for thousands of Chinese graduates.”

Background: Geology

Born into a third-generation Chinese mining family living on Belitung Island, Indonesia, Mimi Ou Yang often described her fascination with gemstones as beginning with a gift from a local miner — a billitonite tektite — Indonesia’s equivalent of moldavite, a natural impact glass formed by a meteorite strike. That unusual “stone from the sky” inspired what she later called her “Stone Dream,” a lifelong curiosity that ultimately led her from geology and mineralogy to Fei Cui jade.

After studying geology in Beijing and later continuing her studies in Hong Kong, Professor Mimi turned her attention to Burmese jadeite jade. Her scientific research would fundamentally alter the understanding of the material for the international gem and jewelry trade.

Discovering Kosmochlor

In 1984, Professor Mimi became the first researcher to identify a terrestrial occurrence of kosmochlor, a chromium-bearing pyroxene previously known primarily from meteorites. Her research showed that Fei Cui was not composed solely of jadeite, but could also contain omphacite and kosmochlor, helping to establish a more complete mineralogical understanding of the material.

“Mimi’s work with fei cui was extremely important. Her contributions to gemology were foundational
in increasing our understanding of this important gem.”

– Richard Hughes, co-founder of Lotus Gemology
and co-author of Broken Bangle: The Blunder Besmirched History of Jade Nomenclature

Yet Professor Mimi’s greatest influence may have come not from the laboratory, but from the language she gave the jade trade.

Type A Jade

As treated jade began appearing in the marketplace during the 1980s, confusion surrounding disclosure threatened consumer confidence. Professor Mimi responded by developing the treatment classifications that would become familiar throughout the industry: Type A, Type B, Type C, and Type B+C jade.

Today, these terms are used by laboratories, dealers, auction houses, and consumers throughout the world.

Much as Richard T. Liddicoat’s GIA diamond grading terminology became the global common language of diamond quality, Professor Mimi’s treatment classifications have become the global language of modern jade disclosure.

Her work helped establish standards of transparency that continue to guide the jade trade today.

She also helped formalize the use of the term “Fei Cui” and promoted a broader mineralogical understanding of Burmese jade, recognizing the relationship among jadeite, omphacite, and kosmochlor. Her work eventually influenced trade regulations, laboratory practices, and international discussions surrounding jade nomenclature.

Christine Rain Chu, Executive Editor of The GAHK Journal, reflected on her long relationship with Professor Mimi:

“For the past 30+ years, Mimi has been both a teacher and good friend of mine. She offered her whole life in gemmology and fei cui study and research.”

In 1987, Professor Mimi founded the Hong Kong Institute of Gemmology and the Hong Kong Gems Laboratory. HKIG became the first overseas academic center to teach Gem-A’s gemmology and diamond diploma courses in Chinese, helping educate generations of gemologists throughout Hong Kong, mainland China, Taiwan, Southeast Asia, and beyond.

HKGL grew into one of Hong Kong’s most respected independent gemological laboratories, particularly in the fields of Fei Cui and jade identification.

Christine Chu added:

“Her lab, the Hong Gems Laboratory, is one of the most authoritative gem labs in HK, especially in fei cui and jade identifications.”

Education remained central to Professor Mimi’s work throughout her life. During a teaching career that spanned more than sixty years, she taught geology, gemology, and jade studies while developing specialized Fei Cui courses and educational materials. She lectured internationally, participated in International Gemmological Conferences around the world, and worked tirelessly to promote gemological education throughout China.

Her accomplishments earned international recognition. In 2000, she was named a Visiting Professor at China University of Geosciences. In 2007, she became only the sixth person ever to receive Honorary Life Membership from Gem-A and the first individual in Asia to receive that distinction. In 2015, she received the JNA Lifetime Achievement Award and the Outstanding Achievement Award from the Hong Kong Jewellery and Jade Manufacturers Association. Additional honors followed from Chinese gemological organizations and academic institutions.

Yet those who knew her often speak less about her awards than about her energy, generosity, and enthusiasm.

Jayshree Panjikar, Secretary of the International Gemmological Conference, wrote:

“Mimi was a wonderful person, full of joy and an evergreen lady with great enthusiasm.”

She added:

“At her age of 90 plus she had taken extra trouble to come to the lab just to meet me… when you know a person for more than 30 years you are not just a colleague but a part of your inner circle of your gemmological family.”

Even into her nineties, Professor Mimi remained active, teaching students, meeting colleagues, and continuing to promote Fei Cui research and education.

Facing opposition from those reluctant to embrace new treatment terminology and disclosure practices, Professor Mimi remained steadfast throughout her career.

“I am a scholar,” she once said. “I must tell the truth to the world.”

That commitment to truth, education, and transparency became the foundation of her life’s work.

Professor Mimi often spoke of her dreams for the future: expanded Fei Cui education, new research initiatives, and continued development of jade studies around the world. Her influence can now be seen in laboratories, classrooms, textbooks, research papers, and gemstone reports throughout the international gemological community.

She summarized her philosophy simply:

“Change your life with knowledge: keep learning and growing; use knowledge to cultivate talents for society, contribute to the country and continue to develop for the world.”

The jade world has lost one of its most important voices. Her influence, however, will continue to be felt by generations of students, researchers, gemologists, and jewelry professionals whose understanding of Fei Cui and gemology was shaped by her life’s work.

Remembering Professor Mimi

Cath Hill

Chief Executive Officer, Gem-A

It was with great sadness that we heard of the death of Professor Mimi Ou Yang Chiu Mei. She was a passionate proponent of gemmological education and champion of Gem-A for many years.

In 1987, hers was the first academic centre to teach Gem-A’s gemmology and diamond diploma courses in Chinese, paving the way for thousands of Chinese graduates.

Mimi passed her Gemmology Diploma in 1979, becoming a Fellow of The Gemmological Association of Great Britain (FGA), and it was a great honour to present her with Honorary Life Membership in 2007 in recognition of her immense service to education in gemmology.

She will be very much missed by the gemmological community.

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Christine Rain Chu

Executive Editor, The GAHK Journal

I met Prof. Mimi Ou Yang in the late 1980s, when I began my gemmology study. For the past 30+ years, Mimi has been both a teacher and good friend of mine. She offered her whole life to gemmology and fei cui study and research.

As principal of The Hong Kong Institute of Gemmology, Mimi trained numerous jewellery and gemmology participants in Hong Kong and China. Her lab, the Hong Kong Gems Laboratory, is one of the most authoritative gem labs in Hong Kong, especially in fei cui and jade identifications.

Prof. Ou Yang established the testing methods of fei cui and clarified the scientific and gemmological relationship among jadeite jade, omphacite jade, and kosmochlor jade in the fei cui family. This gave rise to the scientific clarification and identification of this beautiful and the most important gemstone in the Chinese community.

Professor Mimi Ou Yang also served as Editorial Consultant to The Journal of The Gemmological Association of Hong Kong for decades, helping to bring the journal from its infancy to what it is today.

She is to be missed forever.

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Jayshree Panjikar

Secretary, International Gemmological Conference

With heavy heart I have to inform you that our senior colleague, Ms C.M. Ou Yang — known to us as Mimi — passed away peacefully.

For those who did not know her, Professor Mimi Ou Yang Chiu Mei was an internationally renowned gemologist, mineralogist, and the world’s foremost authority on jade.

I had personally met her in 2023 after the Japan Conference. It was a wonderful meeting. I never thought it would be the last.

Mimi was a wonderful person, full of joy and an evergreen lady with great enthusiasm. At her age of 90 plus, she had taken extra trouble to come to the lab just to meet me.

I felt blessed to meet her again in Hong Kong in 2023. When you know a person for more than 30 years you are not just a colleague but a part of your inner circle of your gemmological family.

Yes, I shall miss her.

May her soul rest in peace.

Goodbye Mimi! Love you!