Here are three really good interactive websites about Gold.
The first is about a treasure hoard found in Europe of gold owned by the Saxons from 650 - 700 AD.
The second two are Australian based interactive activities and focus on the Gold Rush in Australia which was around the same time as the Rush in New Zealand. In the first you are able to look at all the mining techniques that have been used from early days until now. In the second you are a miner in Australia and have to provision yourself, collect the correct equipment, buy a permit than try your luck at mining... I made over £400
in only a few months J