A diamond necklace known as the ‘Mirror Diamond’ necklace and made with colorless rough diamonds and Columbian emerald drops is being put up for a private sale as noted by auction house Bonham.

The necklace is unique as it is made with five Mughal empire pendant diamonds which are believed to be a rare example of the colorless rough diamonds. These diamonds were discovered in the ancient Golconda mines in India in the era of the Mughal rule in the 16th and 17th centuries and were usually reserved for royalty.

The central diamond weighs 28 carats and is noted to be the largest mirror or table-cut diamond known to survive. There are five diamonds weighing between 16 carats to 28 carats which are rare as they are believed to be the largest known matching set of table-cut diamonds from the Mughal 17th century, reports say. The diamonds in total weigh around 96 carats.

According to speculations at the GIA, the five near colorless diamonds belong to the same crystal, reports say.

The necklace is being offered at a price of $20 million, reports add.