The The glazed purple Sang de Boeuf vase was the star find among items taken to be valued at Abbeydale Picture House, on Abbeydale Road, shortly before Christmas.
Charles Hanson, owner of Derbyshire's Hansons Auctioneers and Valuers, which is due to hold another charity valuation at the old cinema next Tuesday, said he was 'delighted' to find such a precious object.
Mr Hanson said: "It is an exceptionally beautiful object and has an estimate of Â£1,000 to Â£2,000. However, it could prove to be a shining star at auction and make much more.
"Chinese ceramics are hugely popular right now. Rich Chinese collectors are keen to buy back their heritage and we have had some stunning auction successes with oriental objects," he said.
"For example, in our December Fine Art sale, three small Chinese bowls sold for a combined total of Â£62,000 from an estimate of Â£500-Â£800 each. They, too, were discovered at one of our free antique valuation days.
“In addition, last autumn we sold an ancient Chinese plate found in a Derbyshire kitchen cupboard for Â£230,000.
"If you have any antique Chinese objects now really is the time to get them valued to potentially sell at auction."
The free valuation day on December 12 was the first of what will be a monthly event at Abbeydale Picture House.
Valuations are free but visitors are invited to donate to St Luke's Hospice Sheffield.
Mr Hanson, who has appeared on TV shows including Bargain Hunt and Antiques Road Trip, teamed up with Sheffield Antiques Quarter to launch the free valuations.
Hendrika Stephens, of SAQ, said: "The hope is these events will get Sheffielders delving around their attics, dusting down their antiquities and coming along to find out if they are sitting on a fortune."
* The next free valuation day at Abbeydale Picture House will take place next Tuesday, January 9, from 10am-2pm, followed by events on February 13 and March 13.