Individuals rather than large mining companies do mining in the Australian opal fields. The reason for this is that opal is particularly elusive; it is not found in great amounts at a particular level or in a particular area, but is found at varying depths beneath the surface and is usually found at levels up to 25 metres deep.
Although in reality all that is needed to get started mining opal is a pick, most miners now consider a jackhammer and an electric hoist