Lazare Kaplan International
American diamond manufacturing and distribution company known for ideal-cut diamonds and the Lazare Diamond brand.
Last updated August 31, 2026
Overview
Lazare Kaplan International (LKI) is an American diamond manufacturing and distribution company founded in 1903 by Lazare Kaplan. The business originated in Ponce, Puerto Rico, where its first factory operated in a district later known as el Barrio de los Diamantes. The factory became one of the largest diamond-cutting and polishing operations in the United States before the company moved its Puerto Rican operations to Caguas during the 1970s. LKI's core activity has been the cutting and polishing of natural diamonds, particularly stones marketed as ideal-cut and fine-make diamonds. These stones have been sold both as loose diamonds and as components of jewelry distributed through the Lazare Diamond brand. The company historically supplied upscale jewelry retailers and other trade customers rather than operating primarily as a consumer-facing retail chain. Its distribution network was reported to include more than 1,500 retail partners and customers in 29 countries. The company developed an international operating footprint over time. It has maintained sales offices or commercial activities in Belgium, Japan, China and Hong Kong, with operations in Japan dating from 1973, Southeast Asia from 1987 and Latin America from 1997. Manufacturing and contract production have extended beyond Puerto Rico and the United States, including operations or partnerships in Russia, China, Thailand, Botswana and Namibia. LKI formed a joint manufacturing relationship with Alrosa, the Russian state-controlled diamond mining company, involving cutting facilities in Moscow and Barnaul. In Namibia, it entered a joint manufacturing and technical-services arrangement with NamGem Diamond Manufacturing Company. LKI's identity has been strongly associated with diamond-cutting science and branded provenance. In 1919, mathematician Marcel Tolkowsky, a cousin of Lazare Kaplan, published a mathematical formula for diamond proportions intended to maximize brilliance, fire and sparkle. LKI became an early commercial-scale adopter of cutting to those ideal proportions. The company later claimed a role in developing the modern oval cut in 1957 and patented a laser-inscription process in 1983. In 2002, LKI and General Electric received a patent relating to high-pressure, high-temperature treatment for improving the color of certain natural diamonds. The company also held patents concerning diamond setting, loose-stone presentation and jewelry displays. LKI became a Diamond Trading Company sightholder in 1946 and was publicly listed from 1972. The Tempelsman Group acquired a controlling interest in 1984, and Maurice Tempelsman served as chairman of the board. In 1985, LKI introduced the Lazare Diamond, described as the first branded diamond launched by the company. This move linked an industrial cutting process to a consumer-recognizable branded product and helped position the company around cut quality and optical performance. The company's later history was dominated by financial, insurance and ownership-related litigation. In 2010, LKI sued Lloyd's of London syndicates and European insurers over the disappearance of diamonds, seeking substantial damages under property insurance policies. In 2011, after defaulting on a loan from KBC Bank, LKI brought a large Racketeer Influenced and Corrupt Organizations Act complaint alleging a conspiracy involving diamonds and money. KBC denied the allegations and successfully obtained dismissal of the United States case in 2019, while related Belgian proceedings continued. LKI was suspended from trading on the American Stock Exchange in September 2009 and had not filed quarterly or annual reports with the United States Securities and Exchange Commission since early 2009. Because the supplied references do not establish the company's current operating, ownership or legal status, those aspects remain uncertain.
History
Lazare Kaplan International was established in 1903 by Lazare Kaplan and began operations in Ponce, Puerto Rico. Its original factory became an important industrial site in the local diamond trade and contributed to the development of a neighborhood known as el Barrio de los Diamantes. During the 1970s, the company moved its Puerto Rican factory operations to Caguas. The Ponce facility had been described as the largest diamond-cutting and polishing factory in the United States. The company's technical reputation developed alongside its manufacturing network. Marcel Tolkowsky, a mathematician and cousin of Lazare Kaplan, published a mathematical model for ideal diamond proportions in 1919. LKI adopted ideal-proportion cutting on a commercial scale during the same year, linking the company to the pursuit of increased brilliance and fire through mathematical precision. LKI later developed the modern oval cut in 1957 and patented laser inscription for diamonds in 1983. In 2002, it received a patent with General Electric for a high-pressure, high-temperature process intended to improve the color of certain naturally formed diamonds. Additional patents covered diamond settings and methods of displaying loose polished stones and jewelry. LKI expanded from a Puerto Rican manufacturing base into an international production and distribution business. It has operated in Japan since 1973, Southeast Asia since 1987 and Latin America since 1997. Sales offices and commercial operations were reported in Belgium, Japan, China and Hong Kong. Manufacturing arrangements included contract production in China and Thailand, facilities in Botswana, and a joint manufacturing and technical-services agreement with NamGem in Namibia. The company also established a partnership with Alrosa involving cutting facilities in Moscow and Barnaul. The company became a Diamond Trading Company sightholder in 1946 and was publicly listed from 1972. In 1984, the Tempelsman Group acquired a controlling interest. Maurice Tempelsman was identified as chairman of the board. LKI's commercial model focused on supplying upscale jewelry retailers and trade customers with loose polished diamonds and diamond-set jewelry. It reportedly served more than 1,500 retail partners and customers in 29 countries. In 1985, the company introduced the Lazare Diamond brand, presenting a branded consumer proposition based on the company's cutting expertise. LKI's later corporate history was marked by severe legal and reporting problems. In May 2010, it sued Lloyd's of London syndicates and European insurers for $640 million in connection with diamonds that had disappeared, claiming that insurance obligations had been breached. In 2011, the company filed a US$1.5 billion RICO complaint against KBC Bank after defaulting on a $45 million loan. The complaint alleged a conspiracy involving the misappropriation of diamonds and funds. KBC rejected the allegations, and in 2019 it obtained dismissal of the United States action. Belgian litigation continued, with a 2020 KBC base prospectus describing proceedings that had reached the Belgian Court of Cassation after LKI initiated a matter in April 2019. LKI's shares were suspended from trading on the American Stock Exchange in September 2009, and the company had stopped filing periodic reports with the SEC in early 2009. The available reference material does not establish whether the company remains active, has completed a formal insolvency or dissolution process, or continues to operate under the same ownership. Its historical significance rests on the combination of large-scale diamond manufacturing, early adoption of ideal-cut proportions, technical patents and the Lazare Diamond brand.
- 2019US KBC case dismissed
KBC Bank obtained dismissal of the United States case, while related Belgian proceedings continued.
- 2011RICO complaint against KBC Bank
LKI filed a US$1.5 billion RICO action against KBC Bank after defaulting on a $45 million loan.
- 2010Insurance litigation over missing diamonds
LKI filed a $640 million claim-related lawsuit against Lloyd's of London syndicates and European insurers.
- 2009American Stock Exchange trading suspended
Trading in LKI shares was suspended in September, and the company had not filed periodic SEC reports since early in the year.
- 2002HPHT diamond-treatment patent
LKI and General Electric received a patent relating to high-pressure, high-temperature treatment for improving the color of certain natural diamonds.
- 1987Southeast Asian operations begin
LKI began operating in Southeast Asia.
- 1985Lazare Diamond brand launched
LKI introduced the Lazare Diamond, described as the company's first branded diamond offering.
- 1984Tempelsman Group acquires control
The Tempelsman Group purchased a controlling interest in LKI.
- 1983Laser inscription process patented
LKI developed and patented a process for laser inscription on diamonds.
- 1973Japanese operations begin
LKI began operating in Japan.
- 1972Public listing begins
LKI became publicly listed, with its shares later traded on the American Stock Exchange under the symbol LKI.
- 1957Modern oval cut developed
The company is credited in the reference material with developing the modern oval diamond cut.
- 1946Becomes a Diamond Trading Company sightholder
LKI became a Diamond Trading Company sightholder.
- 1919Commercial adoption of ideal-cut proportions
Following Marcel Tolkowsky's publication of a mathematical model for ideal diamond proportions, LKI became an early commercial-scale operator to cut diamonds according to those proportions.
- 1903Company founded
Lazare Kaplan founded the diamond manufacturing company in Ponce, Puerto Rico.
Products and positioning
A trade-oriented diamond manufacturer and distributor positioned around precision cutting, ideal proportions, optical performance, branded diamond provenance and supply to upscale jewelry retailers.
Ideal-cut diamondsPolished diamonds1919
Diamonds cut according to proportions intended to maximize brilliance, fire and sparkle. LKI's association with ideal-cut production dates to its commercial adoption of Marcel Tolkowsky-related proportions in 1919.
Fine-make diamondsPolished diamonds
High-quality polished diamonds manufactured for upscale jewelry retailers and trade customers. The company's fine-make stones were distributed both as loose diamonds and for use in finished jewelry.
Lazare DiamondBranded diamonds and jewelry1985
LKI's branded diamond proposition, introduced in 1985. Lazare Diamond products connected the company's cutting expertise with consumer-facing identification and were sold as loose stones or set into jewelry through retail partners.
Diamond-set jewelryFine jewelry
Jewelry incorporating LKI-manufactured diamonds under the Lazare Diamond brand. The available material identifies these products but does not provide a complete catalog of designs or collections.
Flagship businesses
- Lazare Diamond
- Ideal-cut diamonds
Brand decisions
- 2009Trading suspensionOther
LKI had stopped filing quarterly and annual reports with the SEC earlier in 2009.
What changed. Trading in the company's shares was suspended on the American Stock Exchange in September.
Aftermath. The available references do not establish whether the company later restored reporting compliance or resumed trading.
- 1985Launch of the Lazare Diamond brandProduct launch
LKI had historically operated primarily as a diamond manufacturer and trade supplier.
What changed. The company introduced Lazare Diamond as a branded diamond offering distributed through the jewelry trade.
Aftermath. The launch gave LKI a consumer-recognizable brand built around its cutting expertise and ideal-cut positioning.
- 1984Tempelsman Group control transactionM&A
LKI was an established diamond manufacturing and distribution company with a public listing.
What changed. The Tempelsman Group acquired a controlling interest in the company.
Aftermath. Maurice Tempelsman was identified as chairman of the board, and the company continued its international diamond manufacturing and distribution activities.
Leadership
| Name | Title | Tenure |
|---|---|---|
| Maurice Tempelsman | Chairman of the Board of Directorsformer | — |
Controversies
- 2011RICO allegations against KBC BankControversy
LKI alleged in a US$1.5 billion RICO complaint that KBC Bank was involved in a conspiracy concerning diamonds and money after a $45 million loan default. KBC disputed the claims, and the US case was dismissed in 2019.
- 2010Dispute over disappeared diamonds and insurance coverageControversy
LKI sued Lloyd's of London syndicates and European insurers for $640 million, alleging that insurers breached all-risk property insurance policies after diamonds disappeared.
- 2009Trading suspension and missing SEC filingsControversy
The company's American Stock Exchange trading was suspended in September 2009, and it had not filed quarterly or annual SEC reports since early 2009.
Recent events
- 2009LKI trading suspended and SEC reporting lapsed
Trading in Lazare Kaplan International shares was suspended on the American Stock Exchange in September 2009. The company had not filed quarterly or annual reports with the US Securities and Exchange Commission since early 2009.
RegulationOther
Sources
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