Optic Calcite (Iceland spar), formerly known as Iceland crystal is a transparent variety of Calcite, or crystallized calcium carbonate. Originally brought from Iceland & used in demonstrating the polarization of light. It occurs in large readily cleavable crystals, easily divisible into rhombs & is remarkable for its double refraction.
Historically the double-refraction property of this crystal was important to understanding the nature of light as a wave. This was studied at length by Christiaan Huygens & Isaac Newton. Sir George Stokes also studied the phenomenon. Its complete explanation in terms of light polarization was published by Augustin-Jean Fresnel in the 1820s.
The sunstone (Old Norse: sólarsteinn, a different mineral from the gem-quality sunstone) mentioned in medieval Icelandic texts is considered to be Iceland spar. The Vikings used its light-polarizing property to tell the direction of the sun on cloudy days for navigational purposes. The polarization of sunlight in the Arctic can be detected & the direction of the sun identified to within a few degrees.
This can be achieved in both cloudy & twilight conditions using the sunstone (optic calcite) & the naked eye. The process involves moving the stone across the visual field to reveal a yellow entoptic pattern on the fovea of the eye.
The recovery of an Iceland spar sunstone from the Elizabethan ship Alderney, which sank in 1592 suggests that this navigational technology may have persisted after the invention of the magnetic compass.
A super active crystal with strong Divine connections & energy. Encoded with the magic of rainbows. Cleans the environment it is in & removes stagnant energy. Silences mind chatter via connection to higher self & clears confusion bringing clarity & focus. A study stone, held or placed on your desk when wanting to remember information.
Helps you to see the double meaning hidden behind words & actions. Guides one through difficult time & out of the darkness. Reduces tension that can cause migraines & body pains. Excellent cleanser of the aura & great for enhancing meditative states. This crystal amplifies images along with intent & transmits ancient knowledge. A profound healer opening channels of pure light & releasing blockages. Also a solid travel companion that can warn of danger.
Cleans organs, encourages calcium intake, fortifies immune system, reduces depression, releases tension & strengthens skeletal structure.
Crystal System: Trigonal hexagonal scalenohedral
Form/Habit: Crystalline, granular, stalactitic, concretionary, massive, rhombohedral
Lustre: Vitreous to pearly on cleavage surfaces
Specific Gravity: 2.71
Transparency: Transparent to translucent
R.I: 1.658 and 1.486, respectively
Colour: Colorless or white, also gray & pink
Birefringence: 0.154 – 0.1740.154 – 0.174
Fluorescense: red, blue, yellow & other colors under either SW & LW UV phosphorescent
Solubility: Soluble in dilute acids