The International Gem Tower is polishing up West 47th Street. The famous Diamond District between Fifth and Sixth Avenues, also known as Jeweler’s Row, has a brand-new building at 50 W. 47th St. that’s making the dusty block precious again.

The 35-story Extell Development Company tower has just a few full 22,000-square-foot office floors left to buy at $1,000 per foot, said Raizy Haas, a senior vice president, with smaller units for sublease that can be customized for $75 to $85 per foot.

This Skidmore, Owings & Merrill-designed office building is specially designed for jewelry, diamond, and metal dealers who want safety and security. Workers use a unique iris scanner before entering a designated elevator that whisks them directly to their floor. Visitors’ bags will be X-ray screened while discreet cameras watch everyone. A vault, messenger center, valet parking and interior loading docks are part of its 24-hour security amenities.

The Gemological Institute of America owns three floors where gems are rated and future gemologists take classes.

A free 5,250-square-foot fitness center with steam rooms will be ready for tenants this fall.

The IGT’s 12,000-square-foot retail triplex, dubbed the IGT Jewelry Shopping Mall, is a marble-and-mirrored area with 80 feet of frontage. Purchased by the Turkey-based Gülaylar Group, its 50 stalls rent from $6,000 to $30,000 per month, “and more,” said Mahmet Gulay, vice president. Some were set aside to rent after opening this summer.

There is a grand, double-height ceiling with more shops on the overlooking mezzanine and on a lower level. Furnishings are being flown in from Europe, said Gülaylar’s attorney, Barbaros Karaahmet of Herrick Feinstein. Once it opens, it will provide a new sheen to the block.