This article covers in great detail the various geographic regions where Ruby and Sapphire are found, and considers rarity based on country of origin.
Learn how to modify a powder scale for specific gravity testing. A handmade wire basket will make this easy-to-use scale a great tool for gemologists.
Visit one of the top gem hunting spots in the US. Go alone or with the family. A gemology-themed vacation can be fun, educational, and (maybe) profitable.