Porcelain items.

Porcelain items are made for household use and after production changes it become antiques. This add higher value because the texture change and material used from one era to another are different. Blue and White Chinese porcelain has imported and local material for decoration and these two materials give two different blue. Secondly the drawing tells the time. An English expert taught that the best way is by comparing with authenticated specimen. Many dealers, collectors and overseas expert went to look for antique porcelain wares in China but they didn't know that most of the good pieces are no longer there because :

1) Manufacturer do not keep every piece they make and if they make every piece and keep other parts of the world will not know what Chinese porcelain is?
2) Fine house ware and family heirloom were cheaply sold by opium addicts over century.
3) In the 60's Chinese government sold antique porcelain items to pay Soviet Union for the loan taken to fight Korean War.
4) Cultural revolution demonstrators don't believe in dragons and phoenixes destroyed a lot of treasures that was left after the three incidents.

Collectors, dealers and experts always say that there are a lot of imitations. Paintings are copied by other painters. Jade can be old but carving can be new. Bronze ware using acid to etch it slowly makes it look very old. Collectors must know what they have been keeping so that it will not bring a problem to the next generation. A knowledgeable collector will not base on rumour buy , rumour sell. Many collectors don't even have a tool and some doesn't know how to use the tool. Experts always say that imitation can be made exactly the same as originals then we don't need experts to authenticate because we can find makers making genuine artefacts, which is not worth collecting anymore. It is difficult to trust experts who authenticate the items and give oral remarks without producing genuine items and explain how conclusion is arrived. This will lead to confusion and owner will not learn anything.

A discovery that scientific testing done in Hong Kong with certificate of authenticity is not reliable.
In 2003, Thesaurus Fine Arts sold a ceramic teapot purportedly from the Tang Dynasty and a pottery tile supposedly from the Ming Dynasty and both pieces came with ' certificate of authenticity' from scientific testing laboratories in Hong Kong and further tests by two laboratories showed each less than 100 years old and possibly new and another no more than 130 years old and might even be new. ( Extracted from Associated Press)
In 2005, Thesaurus Fine Arts has to pay US$350,000 in penalties and cost. This case happened in Seattle in U.S.A.

All ceramic and pottery artefacts are fakes unless and until proven genuine.