The pearl has opted to stay in its oyster. Jewelry company Mikimoto (America), and its glowing cultured pearls, will restack its offices into 25,000 square feet at 680 Fifth Ave. on the southwest corner of West 54th Street.

Mikimoto will soon occupy most of the 13,000-square-foot fifth floor, which has 12-foot high ceilings and tons of light and will now be contiguous to its current sixth-floor spot.

It will also give up an 8,000-square-foot portion of the fourth floor that it had subleased from The Gap in 2000 when it first moved into the building. At the time, it was represented by a trio from Savills Studley.

The same Savills Studley team, Daniel Horowitz, Jeffrey Peck and Kurt Handschumacher, represented it Tuesday in its 15-year lease, as they did in Mikimoto’s previous expansion here and in its 2008 renewal of its 730 Fifth Ave. store.

JLL’s Frank Doyle, David Kleiner and Harlan Webster represented No. 680’s owner, Josef Buchmann, whose deal is enabling Mikimoto to upgrade its space. The asking rents in the building, also known as Buchmann Tower, range from the low-$70s to the low-$80s per square foot, and the building is managed by Valor Capital Partners.

Mikimoto is celebrating 125 years since founder Kokichi Mikimoto perfected the cultivation of pearls. Twenty years later he started his Black Sea farm, enabling the exquisite living gems to be worn by all.