Published: Nov 09, 2011 5:19 PM EST

GENEVA (AP) - A rare yellow pear-shaped diamond is expected to fetch between $11 million and 15 million at auction next week, and the buyer will have the chance to name it, Sotheby's said Wednesday.
    
The so-called Sun-Drop Diamond is described as fancy vivid yellow - the highest color grading - by gemstone experts. It is the largest known diamond of its kind, at 110.3 carats.
    
"It looks the weight," said David Bennett, the head of Sotheby's jewelry division. "At the same time it's a very bright stone," he added, as a model showed off the diamond to photographers before the Nov. 15 sale at Geneva's Beau-Rivage hotel.
    
The jewel is being sold by Cora International, which discovered the diamond in South Africa only last year - meaning it has no history of previous wearers.
    
"Some people find it very attractive to own a stone that's been lying untouched in the earth for millions of years," Bennett told The Associated Press.
    
Other lots include a suite of jewels given by the Ottoman Empire's Sultan Abdul Hamid II to the wife of the Khedive of Egypt in the late 19th century.
    
The set comprising a necklace, brooch and pair of earrings could fetch $10 million. Some of the gems may have been part of a peace offering given by Russian Czar Peter the Great's wife Catherine to Ottoman Sultan Ahmed II in 1711, Sotheby's said.
    
The jewel auction is preceded by a sale of historic watches Nov. 13. Items include timepieces worn by India's first president, Rajendra Prasad, and a Rolex belonging to German chancellor Konrad Adenauer.
    
The classic gold watch was presented to Adenauer by Rolex's German founder Hans Wilsdorf in 1955. A letter from Wilsdorf explains that Adenauer would be able to wear the watch during his daily bath without harming the mechanism. It is not known if Germany's first chancellor after World War II ever did so.
    
Despite global economic jitters the market for high-end luxury goods remains healthy, said Bennett. Last year, Sotheby's sold a 24.78-carat fancy intense pink diamond for a record-breaking $46 million.

(Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)