Tips for dating English porcelain: Honey and Mercury Gilding-1750-1810

English porcelain, from approximately 1750 to around 1810, used honey gilding; that is honey was mixed with gold into a paste and applied to a piece to be gilded. The result was a rich and soft gilding. Unfortunately, however, honey gilding is also very soft and easily worn away. When that happens, a pink shadowy mark, coinciding with the position of the now-vanished gilding, remains. From around 1805 mercury started to replace honey in the gilding process, producing a harder-looking gilding. Mercury gilding looked more metallic, but was also more resilient to wear. When worn it does not leave the tell-tale pink shadow. It is, therefore, a good rule of thumb for determining whether a piece dates from before 1810.

The obvious detriment of the revised methodology was that the fumes that emanated from the mercury had a disastrous health impact on the poor workers! 

It is worth mentioning, by way of aside, that the workers (usually ladies) who polished the gold after it came out of the kiln were known as burnishers. They used abrasive sticks and other coarse materials to polish the gilding and to remove the harmful oxides.

See the attached image of honey gilding (and the pink shadow) on a fine, but badly damaged, piece.