In general, mineral particles are small, having formed within confined areas such as lava flows or between grains of sediments. Large crystals found in geodes and other rocks are relatively rare.

Have a rock, mineral or fossil you are unsure of? Bring it for the experts to identify. Demonstrations of flintknapping, geode cracking, gold panning, UV fluorescent rocks, silversmithing and rock ...

Every April for the past 20 years, a wide range of rocks, minerals ... Vice President of the Gem and Mineral Society. "It's like breaking open a geode, no two are ever the same.