Gems are pre-polished.
20x Mega Gem Digging Kit Real Gemstones Mining Tool STEM science learning and fun.0 inches (W) x 1.0 ounces Made in United States This kit includes 20 different gems - dig up real Crystal Amethyst Topaz Obsidian and More! Unearthed gems can be quickly matched to the classification guide so kids can log their discoveries.