Iceland Spar Optical Calcite – Double Refraction, China

Iceland Spar is a transparent variety of calcite (CaCO₃) known for its remarkable double refraction, an optical phenomenon where objects viewed through the crystal appear doubled. This specimen crystallizes in the trigonal crystal system and exhibits the typical rhombohedral cleavage characteristic of calcite. With a Mohs hardness of 3, Iceland Spar is relatively soft but durable enough for display and metaphysical use. The crystal's vitreous luster and exceptional clarity enhance its visual appeal, making it a valuable addition to any mineral collection.

This particular raw Iceland Spar has been sourced from China, a region known for producing high-quality optical calcite specimens. The transparency and sharp cleavage planes of this piece allow for clear observation of its double refraction effect, making it both an educational example and a desirable specimen for collectors interested in optical minerals.

Its colorless and highly transparent form is typical of Iceland Spar, named after the original locality in Iceland but now also found in several other parts of the world, including China. The crystal's natural form and clarity make it suitable not only for display but also for metaphysical practices focused on enhancing clarity and focus.

When handling Iceland Spar, it is advisable to avoid exposure to acids or harsh chemicals, as calcite can be easily damaged. Cleaning should be done gently with a soft cloth and lukewarm water to preserve its optical qualities.

China — dominant modern source for collector-grade specimens since the 1990s.