Over the past 30 years, Dan Hausel found 3 world-class colored gemstone deposits, hundreds of diamond deposits & many gold deposits. How did he do this? By studying the geology, geochemsitry and tectonic conditions and keeping his eyes open.
As an example, there are several aluminous gemstones found in rocks that have been subjected to pressures and temperatures equivalent to burial under more than a mile in the earth. The host rocks are usually mica (aluminum silicate) schists and gneisses that are often described as having garnet, kyanite, sillimanite, cordierite or other aluminuous silicates. Such mica schists and/or vermiculite schists are worth exploring. By following such leads, Hausel discovery nearly a dozen ruby and sapphire deposits (aluminum oxides), 3 major iolite (aluminum-silicate) deposits (including two of the largest colored gemstone deposits on earth) & several gem-quality kyanite deposits (see photo gallery). One of these iolite deposits hosts giant gemstones (some potentially weighing >1 million carats) and another deposit, could possibly host as much as 2.7 trillion carats of the gemstone. Multiply that by $15 to $150/carat (the value of faceted iolite).
By keeping his eyes and mind open, he found many deposits. One Hausel enjoys talking about is the Leucite Hills peridot deposit. Peridot is gem-quality olivine. Since the late 1800s, geologists have mentioned olivine in the Leucite Hills. Yes, someone else discovered it, but no one ever looked at it. With his eyes open, Hausel recognized that nearly all of the olivine in the Leucite Hills was gem quality and recovered 13,000 carats of gem material from two anthills on one trip (see photo gallery). Interesting, he also predicted the presence of diamonds in this region, later identified diamond-stability chromites in the volcanic field, but the area still remains unexplored for diamond!
For more information on raw gemstones refer to the following links: