#opticalcalcite — Public Fediverse posts

A contender in this round of #MinCup23, #Calcite comes in several forms, including #Optical Calcite, sometimes called #Iceland Spar or #Iceland Crystal, the strong #birefringence properties are on display in this #photograph as the #crystal creates a small #rainbow-like formation on the right side. This property has made it a candidate for the somewhat mysterious #SunStone from #Viking legend, able to find the Sun despite overcast conditions by looking for the double #refraction.
This form of calcite often cleaves into parallelepiped (parallelogram extended into 3D) sections, such as the one pictured.

Vote in #MinCup23: https://www.mineralcup.org/2023/campaigns/campaigns/campaigns/round-2-match-5

Get a print with this image, or other merchandise at https://heronfox.pixels.com/featured/calcite-specimen-4-heron-and-fox.html

#OpticalCalcite, #IcelandSpar, #Minerology, #VoteCalcite, #Photograph, #MacroPhotography