2) What type of gold is it?
Appraisers have several options for testing precious metals, with acid and electronic testing being the most popular.1 These methods are not foolproof, since they only test the surface, or with filing, just below the surface of a piece. As such, appraisers need to carefully examine the jewellery for signs it may be gold-plated lead or some other inexpensive metal. For confirmation, you may submit for advanced X-ray fluorescence (XRF) analysis. Gold assay offices usually have this equipment and conduct the test for a fee.
Look for stamps and hallmarks. Jewellery may be stamped with a series of marks, such as the metal fineness, the assay office, the maker’s mark, and date letter. These can offer insight into the country of origin, the piece’s age, and the designer, so you can determine the best source for similar jewellery and pricing. (Keep in mind the designer’s signature can be different to the maker’s mark.) Recognizing and understanding these marks require practice and good reference materials.2
You should also consider whether the metal is an uncommon gold alloy (e.g. 19-karat) or a colour that is difficult to attain, such as purple, which is more brittle and difficult to work with. Coloured metal is a clue that additional time or expense was involved in fabricating the piece.
Another point to consider is whether the jewellery is made from new or recycled gold. The answer to this is rarely obvious and appraisers should ask clients about how the piece was acquired. Often he or she will be proud to disclose their jewellery was remodelled from an older piece or whether it was purchased from a vendor that deals in ethically sourced gold.