Starting off the series with one of my favorite crystals to work with.
Optical Calcite amplifies positive energy and like clear quartz it amplifies other crystals it’s around. It helps clear blockages and mental fog. It aids in meditation by connecting you to higher vibrations
Is a profoundly strong spiritual beacon, intensely high vibrational and helps with spiritual and psychic development. Can be a gentler alternative to moldavite.
As a Reiki Master, Optical Calcite’s vivd light refraction is the closest visualization I’ve found to the concept of Universal life force energy
Chakras: Activates all chakras particularly third eye, crown and soul star chakra. As well as clearing your auric field.
Feels like: Channeling reiki universal energy. Blissful and transcendent light. All the colors of light converge into pure white light.
Tarot Card: Queen of Cups. Sometimes viewed as a softer, more nurturing high priestess. She is between the conscious & unconscious world, has complete access to her intuition. She is sensitive, supportive, and has a calm & knowing energy about her.
Iceland spar, also known as optical calcite , is a transparent variety of the mineral calcite, which is a naturally occurring calcium carb
Iceland spar, also known as optical calcite, is a transparent variety of the mineral calcite, which is a naturally occurring calcium carbonate. It holds a special place in optics and mineralogy due to its unique property of double refraction.
Another rock post be upon ye!! How about.... OPTICAL CALCITE
Also called Icelandic Spar or even Viking sunstone!
Despite all of the fancy names, optical calcite is essentially just exceptionally clear calcite. However, calcite is so cool and deserves all the love <3
Fun properties, double refraction, and the reason behind the names below the cut!
Calcite is called Icelandic spar, due to the area it was most famously mined. It may be called optical calcite if it is exceptionally clear. Calcite (CaCo3) has several notable qualities! Some that are commonly used for its identification are: 3 on the Mohs hardness scale, twinning, birefringence (if y'all ever want a brain melting post I will totally deep dive into birefringence for y'all, I'll talk about a lot of the basics of it here!), effervescence with hydrochloric acid, and distinct cleavage planes. The cleavage is probably the most well know! Look at those perfect 6-sided polyhedrons below! It has three perfect cleavage planes at 60-120 degree angles.
However! What I will be talking about most are the optical properties that give this mineral it's nicknames!
Calcite has a very cool property called double refraction! This is a principle of birefringence (which means that light passing through the crystal refracts at different angles for different polarizations. think polarized lenses in sunglasses that block light moving at a specific angle!). Unpolarized light passes through the calcite and is polarized by the crystal! Splitting it into two rays, one moving in the original direction and one splitting off, causing images to appear doubled!
Since the double-image is caused by the distortion of light as it passes through the crystal, the size of the crystal impacts the spacing of the images (as shown above in the chart and below in an example with three pieces of calcite)
The 'ordinary ray" (original path of light) makes an image that stays in place, but rotating the crystal causes the double of the image (the extraordinary ray) to move. The double image occurs if the direction of the polarization is at an angle to the ordinary ray, rotating the crystal 90 degrees can cause the polarizing direction and the ordinary ray to align, eliminating the double image (shown below).
Interestingly, trilobite eyes are made out of calcite! The many lenses of their eyes are all oriented at the C-axis of the calcite crystal, the only axis that aligns the incoming light and polarized direction, eliminating the double image!
NOW TO THE MOST FUN: WHY IS IT CALLED A VIKING SUNSTONE?
When most people think of a sunstone, they think beautiful feldspars with shimmery orange flecks, or of the man-made, glitter-filled orange stone.
When historians came across discussions of sunstones in Norse texts, they at first thought it was a reference to some mythical stone, or perhaps a real stone tied to mythology in its origin. Then, more texts discussed the use of this "sun stone" in navigation. It wasn't until years later that it was proposed that the sunstone could be calcite, because there was no clear description of how to use a sunstone.
There are two proposed methods for using a sun stone in navigation, the simpler dot method and the more commonly accepted color method (not official names, just the easiest way for me to describe them).
The 'Dot method' involves drawing a mark on one side of the calcite piece. Using the properties we discussed before, and holding the stone at the correct angle, you can calculate the direction of the light source by looking through the stone until the double image of the dot on the opposite side turns into one image. Because rotation affects this process, and because some texts refer to the color yellow, this is the less supported theory.
The 'color method' involves moving the stone until it appears yellow, which is caused by a phenomenon called Haidinger's brush. This makes it so that polarizing minerals may show a yellow pattern when facing away from the sun. This pattern appears more distinct against blue backgrounds (e.g., the sky) and is brightest 90 degrees away from the sun. When tested, it was found that you could calculate the East-West direction within a few degrees by finding the two points where the yellow color was brightest and calculating intersection, even when the sun was behind clouds or set beyond the horizon line.
Thanks @earthgeco for requesting more rocks!!! You have activated my trap card. As in. You are now trapped with me as I tell you about rocks. (I have more posts under my rockposting tag as well!)
