The forgery of amber inclusions has an old history. Its peak was reached at the turn of the 19th century, when mainly kaori gum from New Zealand was used to imitate true amber. Forging amber with kaori gum involves melting the gum and placing the desired inclusion into the mould. Some of the imitations are easily recognized as such by containing colourful insects - true amber fossils usually appear monochrome, due to the lack of colour pigmentation.
The most convincing imitations, baffling even the experts, employed a combination of true amber and molten resin. The amber was first cut into two pieces, with a hole drilled into one of them. The insect of choice was then placed inside the opening and then surrounded by molten resin. The other piece was then glued into its original position using more liquid resin. Such inclusions are very difficult to tell apart from natural inclusions.
Amber forgery is widespread. Whether they are interested in an inclusion or a regular piece of amber, buyers should always verify whether they are in fact purchasing real amber.