Mikimoto Akoya Pearl Strand Necklace

A pearl on purpose

Kōkichi Mikimoto was born on January 25, 1858, in Toba, in what is now Mie Prefecture, the eldest son of an udon shop owner. He left school at 13 to sell vegetables after his father fell ill, and as a boy he watched the pearl divers of Ise bring their finds ashore. Judging a pearl exhibition in 1878, at 20, he was struck by how flawed most pearls were.

In 1888 he took out a loan and started an oyster farm at Shinmeiura, an inlet of Ago Bay, with his wife and partner Ume, and in 1890 he took advice from the zoologist Kakichi Mitsukuri. On July 11, 1893, after many failures and near bankruptcy, he produced hemispherical cultured pearls at Ojima, a small island off Toba. Those first pearls were still attached to the inside of the shell. He received Japanese patent No. 2670 for the method in 1896.

A round, free pearl was harder. Mikimoto found round pearls among oysters hit by a red tide in 1905 and was granted another patent in 1908, but at the same time Tatsuhei Mise and Tōkichi Nishikawa developed methods of implanting a nucleus with a piece of living oyster tissue. Mikimoto adopted their combined method around 1916, which made commercial round cultured pearls possible. A 2024 review by a former researcher at the company's own pearl institute cautions against crediting the round cultured pearl to any one person.

Selling a new kind of pearl

In March 1899 Mikimoto opened the Mikimoto Pearl Store in Ginza, a direct outlet where staff could explain to customers what a cultured pearl was. A jewelry workshop followed in 1907, and a London branch opened in 1913. Around 1920, when round cultured pearls reached Europe, parts of the natural-pearl trade tried to have them treated as imitations. Scientists concluded the nacre was not fundamentally different, and legal proceedings in Paris ended in the cultured pearl's favor in 1924.

Mikimoto fought on quality as well. In 1932 the company publicly burned inferior pearls outside the Kobe Chamber of Commerce, a stunt meant to show it sold only good ones. By 1935 there were 350 pearl farms in Japan producing 10 million cultured pearls a year. The factory was destroyed in 1945; after the war the business reorganized and merged its production and retail companies as K. Mikimoto & Co. on December 1, 1972.

The New York store on Fifth Avenue opened in 1975. Mikimoto has made jewelry for Japan's imperial family, including a 2013 parure for Princess Kako, and crowns for beauty pageants. In 1985 the Japan Patent Office named Kōkichi Mikimoto one of Japan's ten great inventors. He died in 1954. Ojima, the island where he first succeeded, is now Mikimoto Pearl Island, a museum and visitor site.

The famous strands

The best-known Mikimoto strand belonged to Marilyn Monroe. It is a 16-inch choker of graduated akoya pearls with an 18-karat white gold and diamond signature clasp, associated with her February 1954 trip to Tokyo with Joe DiMaggio. One report says it was a gift from the Emperor of Japan, and that it was one of the few pieces of fine jewelry Monroe owned; she reportedly preferred costume jewelry.

Monroe later gave the necklace and its box to her friend Paula Strasberg, whose daughter Susan sold it in 1998 with a letter describing its history. Mikimoto bought it back at auction that year for an undisclosed sum. It is not for sale, is kept by the company's U.S. arm in New York, and is shown only on special occasions, as it was in Houston in November 2022.

The standard 18-inch strand in this entry is a current catalog model rather than a single object. Mikimoto sells it in several pearl sizes and two quality grades, so two strands sold under the same name can differ widely in price.

How to read a strand

Akoya pearls come from the Pinctada fucata martensii oyster. According to the GIA, they are known for their round shape, high luster and a rosé, or pink, overtone that is very often the result of processing. They are generally small, averaging between 6 and 8 mm, and akoya pearls above 10 mm are considered rare.

Mikimoto's U.S. site lists this 18-inch white gold clasp model in A and A+ quality and in pearl sizes of 6x5.5, 6.5x6, 7x6.5, 7.5x7, 8x7.5 and 8.5x8 mm. The headline price of $5,100 in October 2026 applies to the smallest configuration, 6x5.5 mm in A quality. The product description says the strand features pearls 'anywhere from 6.5-8mm,' which is the range this listing's record uses, so compare strands by pearl size and grade, not by name alone.

The model is defined by its 18-inch length and Mikimoto's signature clasp in 18-karat white gold; the same pearls on a different length or clasp metal are a different catalog item with a different price.

Why it is the benchmark

Before Mikimoto, a matched necklace of round pearls meant years of collecting natural pearls one at a time. Cultured pearls made the classic strand something a jeweler could reproduce, and Mikimoto's own name became shorthand for it.

The company has stretched that legacy in new directions, with a Comme des Garçons collaboration in 2020 and a Chrome Hearts collaboration in 2024, aimed partly at younger customers and men. The 18-inch akoya strand with a white gold clasp remains its core classic.

The numbers

Pearl type

Akoya cultured pearls (Pinctada fucata martensii)

Pearl size

6.5-8 mm per the maker's description; offered from 6x5.5 mm to 8.5x8 mm

Quality grades offered

A and A+

Length

18 inches

Clasp

18-karat white gold Mikimoto signature clasp

Maker

K. Mikimoto & Co., Ltd., Tokyo

Timeline

1. Jan 25, 1858

   Kōkichi Mikimoto is born in Toba.

2. 1888

   Mikimoto starts raising akoya oysters at Shinmeiura on Ago Bay.

3. Jul 11, 1893

   Mikimoto produces his first hemispherical cultured pearls at Ojima.

4. 1896

   He receives Japanese patent No. 2670.

5. Mar 1899

   The Mikimoto Pearl Store opens in Ginza, Tokyo.

6. 1908

   Mikimoto receives patent No. 13673 for his own round-pearl method.

7. 1913

   A London branch opens.

8. 1916

   Mikimoto adopts the Mise-Nishikawa nucleus-and-tissue method, enabling commercial round cultured pearls.

9. 1924

   Legal proceedings in Paris end in favor of cultured pearls.

10. 1932

    The company publicly burns inferior pearls in Kobe.

11. Feb 1954

    Marilyn Monroe visits Tokyo with Joe DiMaggio; her Mikimoto choker is tied to this trip.

12. Dec 1, 1972

    Mikimoto's production and retail companies merge as K. Mikimoto & Co., Ltd.

13. 1975

    Mikimoto opens a store on Fifth Avenue in New York.

14. 1998

    Mikimoto buys back Monroe's choker at auction.

15. Oct 2026

    The 18-inch akoya strand with white gold clasp is listed from $5,100 at the maker in the U.S.

The world in 1893

• Jan 17, 1893

  The Kingdom of Hawaii is overthrown.

• Feb 23, 1893

  Rudolf Diesel receives a patent for the diesel engine.

• May 1, 1893

  The World's Columbian Exposition opens in Chicago.

• May 5, 1893

  A crash on the New York Stock Exchange sets off the Panic of 1893.

• Sep 11, 1893

  The World Parliament of Religions opens in Chicago.

• Nov 7, 1893

  Women in Colorado win the right to vote.

• Dec 16, 1893

  Dvořák's Symphony No. 9, From the New World, premieres at Carnegie Hall.

Price record

This is an asking price, not a sale. It is what a seller wanted on the date shown. Asking prices often sit above what buyers pay, but an ask is not a ceiling: a sale can land on either side of it. It is not a value.

By reference price, Mikimoto Akoya Pearl Strand Necklace is number 84 of 100 in the jewelry entries of the FLOAT 100. 44 of those 100 rest on a realized sale; the rest carry an asking price or a guide value, and each page says which. Rank within the FLOAT 100 itself (84 here) is editorial: how much an object defines its field, not price alone.

Did you know

• Mikimoto's first cultured pearls in 1893 were half-pearls stuck to the inside of the shell, not round ones.
• Kōkichi Mikimoto left school at 13 to sell vegetables.
• In 1932 his company publicly burned low-quality pearls to protect its reputation.
• By 1935 Japan had 350 pearl farms producing 10 million cultured pearls a year.
• Mikimoto bought Marilyn Monroe's pearl choker back at auction in 1998 and keeps it in New York.
• The island where the first cultured pearls were made is now called Mikimoto Pearl Island.
• Akoya pearls above 10 mm are considered rare, according to the GIA.