Iceland Spar $44.99Iceland Spar is a clear, naturally formed variety of calcite known for its optical clarity and distinctive transparency. Often used in classrooms and collections to demonstrate light refraction and double imaging, this mineral is a favorite among geology students, educators, and anyone curious about the science of crystals. Its crisp, glasslike appearance makes it an eyecatching piece for display or handson learning. Why you'll love this: Transparent