A rare collection of around 38,000 Spanish coins will be auctioned by Sotheby's New York on behalf of the Hispanic Society of America.

The auction house said the collection is a unique assortment of assembled by the founder of the Hispanic Society, Archer M. Huntington, and is expected to rise between $25 million to $35 million for the society.

Included in the exclusive collection are rare 50 large gold coins from the era of Christopher Columbus' expeditions known as excelentes. Besides this, there is a range of coins dating back to ancient times in Spain.

According to Fox News, some of these pre-Roman coins are from the period when a number of cultures, including Celts and Phoenicians, inhabited what is now Spain. The Islamic period after the year 711 is also represented in the collection.

The Hispanic Society, founded in 1904, houses many rare books and manuscripts, art and artifacts from Spain, Portugal and Latin America. Some of the most notable works in its museum are by Diego Velázquez, Francisco de Goya, El Greco and Joaquín Sorolla y Bastida.

The New York Times reported that the auction is a much-needed source of revenue for the Hispanic Society of America, a museum and research library in Washington Heights in Upper Manhattan that has long struggled to raise its profile to attract visitors and donors.

The decision to allow the auction of the collection reportedly took place after an extensive review of their place within the society and it was found that the coins were never officially a part of the museum's collection.

The Spanish collection will be on display at Sotheby's New York during February.