1. Nuggets in laterite (ironstone): This is the most common type, the result of chemical weathering and deposition. These nuggets are high purity as they form very near the surface, and the ironstone erodes out of them. Those actually found on the surface are as clean as you can get them. They often have lots of character, in that they are knobbly with convex and concave facets. Some have reddish ironstone, most have black. Some have so much ironstone that you can only see a glint of gold. Nuggets that form one, two or three feet below the surface often have calcrite (whitish pink) and alumnina (yellowish brown) inclusions.

2. Nuggets in glacial streams: These form in the schist traps. They are less pure, and are often pale, rounded and very small. They have no matrix. If you want some of these first hand, go to the freezing streams of New Zealand or Alaska with a pan. It is brutal work.

3. Nuggets in quartz: Sometimes gold is deposited in a continuous vein, and when there is enough gold the specimen can be described as a nugget. These nuggets are from the upper parts of the original gold deposit. They formed in the boiling off zone of the hydrothermal. They were often well above present ground level. In parts of Australia they are over 2.5 billion years old, and now only scattered specimens remain on the ground below the point of their formation. Sometimes the quartz is as a white as snow, but most times it is heavily stained with black and brown oxides and sulfides. It is hard to buy and sell, as the novice has a hard time determining the actual gold content and purity of the piece. Most often these pieces as specimens have a value far above that of their gold content. Attractive pieces are rare and highly sought after.

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