A pair of 17th century eyeglasses is expected to fetch millions of dollars at an auction next month.

It is believed that the two jeweled glasses, which feature lenses made of diamonds and emeralds instead of glass, were originally owned by members of the royal family of the Mughal Empire, which ruled the Indian subcontinent.

Both glasses are scheduled to be shown to the public for the first time ever in Hong Kong, New York City, and the British capital, London, before the scheduled sale date in October.

The pair are an exceptionally rare example of Mughal jewelry making, said Edward Gibbs, Sosby’s regional director for the Middle East and India, adding: “As far as we know, they are unparalleled.”

The pairs are expected to sell for between £1.5 million and £2.5 million ($2.1 million to $3.5 million) each, according to the auction house’s estimate.

The rarity of the two pieces is also due to the sheer size of their gem lenses. The two lenses in one pair, known as “halo of light” glasses, are believed to have been cut from a 200-carat diamond found in the states of Andhra Pradesh and Telangana in India.

Meanwhile, the second pair’s green lenses, dubbed the “Gate of Heaven”, are believed to have been cut from a Colombian emerald weighing more than 300 carats.

Source: CNN