The largest sapphire fields in the Southern Hemisphere lie here, in Queensland's Central Highlands: Anakie, Rubyvale, Sapphire and The Willows. Like many of the wonders along the Tropic of Capricorn, the Sapphire Gemfields are a product of incredible time and drastic changes in climate and environment. Between 70 and 40 million years ago, as the earth's crust shifted, moving Australia closer to its current position, hot spots developed below. Plugs of the Mount Hoy Basalt erupted spewing out basaltic ash and lavas. Abundant sapphires and zircons that had formed deep in the earth's crust, blasted out as crystals in the volcanic ash. What gemstones might I find on the Sapphire Gemfields? Sapphires come in all shades of the rainbow, although they are typically a deep, royal blue. The Sapphire Gemfields are famous for rich, golden yellow and parti-coloured stones and are also home to the famous black star sapphires. Heading West Carry on to Alpha, where dramatic shifts in Tectonic plates formed the Drummond Range - look out for petrified wood. Heading East Pass through Emerald, the hub of the Central Highlands. Outside the Town Hall you will find a fossilised tree trunk estimated to be 250 million years old.