'Iceland Spar' is the name commonly given to Calcite when it forms in transparent, colorless double refractive crystals. Double refractivity is caused by the internal crystal structure of Calcite. When a ray of light enters the crystal it gets bent (refracted) twice before exiting again. If you look at a line of text through an Iceland Spar like you would a magnifying glass the image you see will be doubled.

Because of this special property Iceland Spar is often used magically to double the power of a spell or ritual, and is an excellent addition to charm bags for any purpose. Like all forms of Calcite, Iceland Spar is said to be helpful for opening doors of opportunity and increasing the number of 'lucky' chances you encounter in life. It is also said to open the mind to new solutions for old problems, make you more adaptable to change and more prepared to take full advantage of unexpected opportunities when they arise.