6. Corundum
Wait a minute, corundum is just a mineral, right? Yes, and being relatively common mineral found in all kinds of rocks (igneous, metamorphic and sedimentary) and very hard and nicely colored, it has great properties for being a gemstone. Some of the most valuable gemstones, such as ruby and sapphire are actually varieties of corundum.
![7 Easiest Gemstones to Find in Rocks and Creeks](https://imonkey-blog.imgix.net/blog/wp-content/uploads/2017/07/01125850/ruby-1468722_1920-750x500.jpg?auto=fortmat&fit=clip&expires=1750032000&width=480&height=320)
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