Design Your Perfect Ring
From selecting the perfect diamond to finalising the ring design
our bespoke ring service lets you personalise every step and
bring your dream ring to life.
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Our Legacy
KOS is a sub-brand of CELI Jewelry, a heritage family business with over 50 years of mastery in natural diamonds and fine gemstones, established in 1975.
Building on decades of expertise, our GIA-certified gemologists meticulously select only diamonds of exceptional cut and brilliance. To bring your vision to life, we offer an extensive inventory of over 1,000 lab-grown diamonds covering every shape, carat weight, with the best quality grade. Whether you are crafting one-of-a-kind lab-grown diamond rings or seeking a truly personalized jewelry design experience, our team is ready to guide you at our CentralWorld flagship store in Bangkok.
Every piece is brought to reality in our dedicated in-house production facility. Handcrafted by master artisans who have passed down meticulous goldsmithing techniques across generations, each creation undergoes stringent quality control before reaching your hands—delivering enduring value and impeccable craftsmanship.
50+ years experience
in diamond industry
With over 50 years of experience, we take pride in our expertise in diamond jewelry. Every diamond is hand-selected by GIA-certified gemologists, and our highly trained jewelry advisors are ready to provide technical knowledge and comprehensive advice, ensuring trust and confidence in your purchase.
Customizable
design
We offer a personalized jewelry design service, allowing you to create a piece that truly reflects your individuality. By working closely with our expert team, you can customize every detail, ensuring your jewelry is as unique and special as you are.
In-house
Craftsmanship
Our in-house production guarantees meticulous attention to every detail, delivering exceptional quality in every piece. With decades of craftsmanship, we are committed to creating masterpieces that reflect both artistry and precision, tailored uniquely for you.
Certified by
GIA and IGI
Every diamond is certified and graded by globally recognized institutions such as GIA and IGI, which are renowned for their rigorous grading standards. Each diamond is also laser-inscribed to ensure it matches its certification.
GIA & IGI CERTIFIED
All of our diamonds are certified and graded by world respected institutions, GIA & IGI, who are widely recognized for its strict grading standards and is considered a reputable source for diamond certification. The certificate serves as a reliable and independent assessment of a diamond’s quality, aiding consumers and the diamond trade in making informed decisions when buying or selling diamonds. All of our diamonds are laser-inscripted to ensure the diamond matches with the certificate.
Knowledge
A Scientific Breakdown: Lab-Grown Diamonds vs. Moissanite vs. Cubic Zirconia (CZ)
Summary: To the naked eye, these three gemstones might offer a similar dazzling brilliance, but their molecular structures are entirely
Big Carat or Flawless Color? Unfolding the 4Cs to Maximize Your Lab-Grown Diamond Budget
Summary: Navigating the 4Cs of diamond specifications might seem complicated at first. However, the real key to knowing exactly how
Eco-Luxury: A Deep Dive into the Creation of Eco-Friendly Diamonds
Summary: The modern definition of luxury has moved beyond mere brilliance and carat size to the transparent and verifiable value
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