SINGAPORE - Those dealing with gold on a regular basis are often able to tell the real McCoy by touching and holding it.
But this is often very subjective and fake or low-grade gold can often slip under the wire.
Those unsure about the grade of their precious metals, like gold, silver, platinum or palladium, can send them for testing at the Singapore Assay Office (SAO) for a fee.
The fee varies based on quantity.
Testing is needed here because unlike in some countries such as Britain, the quality of precious metals sold here does not have to be verified or hallmarked.
When an item has been verified to be of satisfactory quality, it is marked with the laboratory's logo.
Here are 3 ways the quality or fineness of gold can be tested:
1. Touchstone/carat needles
An ancient way of testing that dates back to 500BC. Gold is rubbed against a dark stone, usually quartz or jasper, which leaves a mark on the stone.
That mark is compared with a similar one made by a real piece of gold.
Next, a few drops of nitric acid are added onto the mark. As gold is a non-reactive metal, the mark will remain on the stone.
This is usually followed by aqua regia (a mix of nitric acid and hydrochloric acid), which will make the mark disappear.
Most pawnshops and traditional jewellery shops still use this testing method.