#icelandic spar

[vpofcookies]

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!)

Image sources: 1, 3, 4, 7, 9, 10

Images from me: 2, 5, 6, 8

[geologyin-blog]

Iceland Spar is a crystalline mineral known for its double refraction phenomenon. When light passes through Iceland Spar, it splits into two separate rays, creating a captivating visual effect. This unique property earned Iceland Spar its nickname "Viking Crystal," as it is said that ancient Norse seafarers used these crystals as navigation aid

[rock-and-rolly-polly]

Iceland Spar Calcite

I got it for day 9 of my advent calendar

[pedaloftheday]

The Iceland Spar is a dual channel looper like you've NEVER SEEN BEFORE...check out our demo to hear this one in action!!

[kieselguhrkid]

Part 2. Iceland Spar Against the Day by Thomas Pynchon

[california27]

[icarus-suraki]

They:

Licensed fandom merch this, pfp fandom merch that, meanwhile I spent entirely too much actual money on a giant chunk of Iceland spar because of fucking Against the Day.

[filurig]

its been a while but new pareidolia creature!! ive been thinking of making these for a while. in case u don't know what an älgfrode is (a bit more of a niche nordic mythology creature), an älgfrode (or elgfróði in icelandic) was mentioned in hrólfs saga kraka, one of the old norse hero sagas. while the context for that was one specific character i just wanted to make moose people..

more info abt my creatures below the cut...

they wear more clothes than in the ref this is just to show their anatomy LOL. clothing is actually very important to them and textiles will almost always have a role in any tradition/significant social event. their textilework is very renowed and is one of the trades that cause some other vättar to want to trade with them as mentioned in the ref!

one potential reason for their high level of defensiveness is that their species suffers from a higher than average infant mortality rate - with time, this mortality rate has lowered from what it used to be, but when the species first appeared, it wasn't unusual for a mother to have to give birth to many calves before one even made it to adulthood. this rooted a deep set vigilance in them - even now that the rates have stabilised a bit. the high mortality rate was probably due to the affected "shift" gene sometimes activating improperly which could result in stillborns. with time and selective pressure new gene mutations would arise in the species that "counteracted" the instability of the first initial one and made the infant mortality decrease. it is, however, still a little higher than usual for similar species, and so it is traditionally encouraged to have many children.

gender roles for älgfroder are interesting - there is a strong sense of "equal strength", or "laorhgr" in älgfrode, which is important. while males are usually slightly larger than females, there is emphasis on the importance on a pair being able to stand their ground both physically and emotionally to the other and a relationship can only go ahead if a spar between two älgfroder is fair. this extends to an interesting dynamic that involves polyamory. älgfroder can be both monogamous and polyamorous, however polyamorous relationships often only arise when there is a big physical differential between two parties. the belief is that if one party is stronger than the other, that strength can be equalised if the other party is accompanied a second partner of similar strength - usually this happens between one strong male and two females on the smaller end. that way the resulting relationship has achieved "laorhgr". this ofc varies as everything does but ya. basically if you are a big strong älgfrode dating a small petite älgfrode it's seen as shameful and barbaric. there is also a bias to heterosexual relationships as it is seen as an important social duty to at least successfully raise one calf.

dhukohr are the more commonly occuring intersex condition in älgfrodar, but there is an equivalent to it for "males" where they fail to grow antlers and have very small dewlaps due to low testosterone levels - those are usually referred to as kvikohr. they are often recognised as their own gender respectively however there are many that identify as men/women too. some of these dhukohr/kvikohr are actually moreso trans than intersex - simply having utilized faerie dust in order to transition. this can be a bit of an ordeal though because usually this requires being administered it by a tomte which, depending on the settlment, can be a tense negotiation, although individuals usually have a less hard time with that.

älgfrodar and bäckahästar can hybridise and do sometimes produce fertile offspring! i would have to think more about this though erm. but i think it does and can happen. there is a sense of rare camraderie between the two species in many cases but especially so between älgfrodar and bäckahäst communities that choose to spend more time as their faun shift than their base shift - in fact a few of these bäckahästar choose to integrate into certain älgfrode settlements, but this is more of a rare occurance. most bäckahästar that possess "unishift" clothing have actually had them made by älgfrodar, or at least had the fabric sourced from them

[reddpenn]

Do you have any neat calcites?

Do I ever!! Here are just a few of my favorites.

Here’s a specimen of huge brown barite crystals on a druzy of yellow calcite, from Elk Creek South Dakota.

Under a long wave UV light (365nm), the calcite fluoresces yellow, and the barite fluoresces pale blue.

The barite also has very strong yellow-green phosphorescence, meaning it glows in the dark for a while after the UV light is removed!

This is mangano calcite, a form of calcite that gets its faint pink color from manganese.

This specimen features lenticular crystals and a cool “pagoda” formation!

And of course, here it is showing off what mangano calcite is most famous for: its gorgeous orange-pink fluorescence.

Here is some classic optical calcite! Although it’s often called "Iceland Spar", this particular specimen is from Mexico.

Optical calcite is known for its birefringence, an optical effect in which it doubles the image behind it! This is because calcite’s crystal structure polarizes the light passing through it, splitting it into horizontal and vertical wavelengths. All calcite technically does this; we can just see it happening in optical calcite because it is very clear and easy to see through.

This beautiful, water-clear specimen of dogstooth calcite crystals is from Linwood Mine in Iowa. It features very distinct phantoms!

Phantoms form when a thin layer of some other mineral begins growing on the surface of the crystal. As the calcite continues to grow, that layer becomes trapped inside of the crystal, becoming a faint record of the crystal’s size and shape when it was much younger! Calcite phantoms are especially interesting because their image is distorted by birefringence.

This piece is a columnar calcite from Fujian Provence, China! Note the uncommon column shapes of the crystals.

It fluoresces a lovely orange red!

And of course my favorite calcite of all! This specimen is cobaltocalcite from Morocco. While that hot pink color looks totally dyed and fake, it’s actually completely natural! Cobaltocalcite gets its distinctive color from atoms of cobalt in its molecular structure.

There's more calcite in my collection, but these are the best, I think!

[killuasghost]

SLICES OF LIFE # ！︎

↠︎ plot + warnings: hcs on college!jjk men with f!reader roommate and their many adventures with one another!

↠︎ featuring: nanami, toji, choso, gojo, and geto

↠︎ continuing my college!jjk series and we're starting with this! i love the idea of reader having her own relationship with the boys and vice versa!

➞︎ it isn't often that you guys get to go on adventures together.

➞︎ most of the time its a bunch of mini side quests with one another at different times.

➞︎ when you have afternoon classes, gojo and geto are usually finishing up their day as well.

➞︎ which turns into the three of you taking the train into tokyo, blowing gojo's money on sweets and food.

➞︎ sometimes you guys catch a car meet on the off chance y'all end up on that side of town when its happening (a/n: i hc the group to be into cars but geto, toji, and choso are the biggest gear heads)

➞︎ some days, you and nanami spend mornings together.

➞︎ mostly spent in the nooks and crannies of libraries or by the window in a bakery/cafe.

➞︎ sometimes, when you guys have book club, he'll put together a picnic for the two of you.

➞︎ there's a garden with a bunch of Japanese maple trees that the two of you found once.

➞︎ it's y'all's secret third spot. 🤫

➞︎ surprisingly, choso started tagging along with you to toji's practices/matches after a couple months of you doing it.

➞︎ while you were focused on the 'pr' side of things for the boxer, choso took on the role of sparring partner.

➞︎ so now, you had not one, but two gym bros on your hands as choso started hitting the gym srsly.

➞︎ don't worry, it's not always a fist fight with those guys.

➞︎ choso is always finding some new spot to try, mostly art or herbal shops, and toji drives while you tag along for the ride.

➞︎ meanwhile, toji's always finding some mountain to hike! gd its exhausting keeping up with him sometimes!

➞︎ but they're the only two to stick around for when you have your 'bring it on' marathon, so you endure :)

➞︎ geto is in the tattoo shop late at night some weekends and whenever you're available, you pop a squat on the comfy futon he has in his space and chill.

➞︎ he appreciates the company whenever he's working on a client after hours or working hard on designing a new piece.

➞︎ he uses you as a gauge for when he's been working too long. if you've been silent for more than an hour, he knows it's time to wrap it up.

➞︎ gojo is a slut for his monthly massages. he got you one as a birthday gift one year and y'all have been going together ever since.

➞︎ he's always the one you're trying bazaar shit with. cos why tf did he fire up the private jet just so the two of you could visit the blue lagoon.

➞︎ in ICELAND btw

➞︎ toji secretly likes to cook.

➞︎ like loves to cook actually.

➞︎ you only found out when it was just the two of you at home one weekend (nanami on a business retreat with geto, gojo visiting his family (begrudgingly he says), and choso went camping with his brother's) and toji threw down after the joint sesh y'all had.

➞︎ i mean the spread was spreadin'

➞︎ he swore you to secrecy, cooking was smth he didn't want the other's taking advantage of (he's just scared of rejection ((that wouldn't happen)) 🙄).

➞︎ one time y'all took a dessert class and learned to make matcha swiss rolls 🤤

➞︎ toji looked cute in his lil apron and hat ;)

➞︎ choso invites you to art exhibits with him and drags you along to the newest infrastructure being built in the city

➞︎ there's a local pottery/glass blowing shop in downtown Sendai, that the two of you frequent to make clay pottery.

➞︎ at some point, choso designs the most beautiful sculpture out of clay and all of you show up for he showcases it at his first art show!

➞︎ you were the sculpture

➞︎ every once in awhile you guys link up for a group activity.

➞︎ its usually toji's fights but most recently you guys went to the opera!!!

➞︎ geto somehow ended up on stage for a brief moment but that's a story for another time cause 😅

FREE PALESTINE, CONGO, SUDAN, EVERYWHERE !!!!

[honeybubbledivination]

What Crystals Could Be Useful To You Right Now? 🍯

Hey, busy bees! The image you choose will correlate with a card from ‘Mood Crystals’ by Christel Alberez & Nerissa Alberts! Each card expresses an emotion that you could be stagnant in, one you’re trying to embody, or trying to transmute! The card then offers crystal options to utilize and three combinations of crystals to test out together on your journey with the energy you’re situated with! I hope I’m able to bring some guidance! This is just for funsies! I’m not a legal or medical professional! If you’d like a personal reading, dm me for details!

1→2 ↓ 3→4

Option One:

Physical Emotions - Bored:

Option One! You’re bored out of your mind! Or at least a little lower energy than you’d like! Your creativity may be blocked right now or you feel caught up in day to day life! For activities, I’d recommend trying something new! Or getting back to basics! Doodle for a few minutes, listen to music, find a new recipe to try, or go for a walk and take some pictures! Below are some recommendations for stones to help your energy out! I hope they help!

- Bunny 💛🍯

Stones Recommended: Orange Calcite, Fluorite, Quartz, Fulgurite, Smokey Quartz, Picture Jasper, Iceland Spar (Clear Calcite)

Powerful Stone Combos: Fulgurite + Smokey Quartz, Orange Calcite + Iceland Spar, Fluorite + Quartz

Option Two:

Energetic And Transformational Flow - Sensual:

Option Two! Your energy is the opposite of option one! You guys are on a ball! Maybe you’re looking for a way to sensualize yourself and your energy. Give it purpose and poise. Or you’re looking to embrace your body. Maybe you have a low sex drive and you’re looking to change that! I recommend doing some meditative exercises to open up to your sensuality! Find something that makes you feel sensual or even seductive. Regal is a word that comes to mind as well. Music, outfits, things that inspire you to be present and physical in your body. Give yourself some TLC! In whatever way that means! The stones below should help guide and inspire your energy on your journey with sensuality!

- Bunny 💛🍯

Stones Recommended: Rhodochrosite, Orange Kyanite, Shiva Lingam, Fire Opal, Blue Topaz, Blue Calcite, Zincite

Powerful Stone Combos: Orange Kyanite + Shiva Lingam, Rhodochrosite + Fire Opal, Blue Calcite + Shiva Lingam

Option Three:

Energetic And Transformational Flow - Frustrated:

Hey, Option Three! Sounds like you’re frustrated lately! This could be from a situation that experienced stagnancy or it could be frustration with yourself! Be patient with yourself and this situation! An outcome is on the horizon! The stones below should help with your journey in handling this frustration!

- Bunny 💛🍯

Stones Recommended: Aquamarine, Dog Tooth Calcite, Amethyst, Petrified Wood, Serpentine, Snowflake Obsidian

Powerful Stone Combos: Aquamarine + Amethyst, Serpentine + Amethyst, Serpentine + Dog Tooth Calcite

Option Four:

Mental Clarity - Over Whelmed:

Option Four, you’re overwhelmed. You’ve taken in too much at once and haven’t had a minute to yourself to just sit with it. Your mind is jumbled and racing and we need to fix that! Try something low energy and relaxing. Find a quiet hobby to enjoy that is therapeutic and has absolute nothing to do with what’s happening around you. I hope the stones listen help guide you in calming down and enjoying the journey that is life!

- Bunny 💛🍯

Stones Recommended: Sodalite, Zoisite, Opal, Lapis Lazuli, Black Tourmaline, Smoky Quartz, Chrysanthemum Stone

Powerful Stone Combos: Lapis Lazuli + Smoky Quartz, Sodalite + Zoisite, Opal + Black Tourmaline

₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊ ˚

Bunny’s Notes: This is a little bit of a low energy pac! I’m a bit booked and busy right now, but I wanted to provide a reading for all my busy bees! Thank you so much for your support and patience! I still have some openings for paid readings if anyone is interested! Dm me! Love and light! ᕱᕱ ₊⊹ ᰔ

₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊˚⊹⋆ ₊ ˚

[geologyin-blog]

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.

[regexkind]

From my drafts:

I strongly believe that the Roman legionaries who deserted in Gaul have been reincarnated into marble sculpture avis who still jerk off to redheads

It's so much worse than all that.

I don't think they're reincarnated. I think that if you're sufficiently fanatical—about anything, really, but in this case, about RETVRN-style shit—your personhood shrivels away like a desiccating carrot under the vegetable drawer. And then anything can get in. In this case you get too rhapsodic about homesteads with your Aryan wife or whatever and then POOF suddenly there's a legionary rattling around in there instead, two sets of memories overlapping like distorted light through Iceland spar, one modern and one millennia old. The legionary peers out through the cracks in your skull and sees redheaded women who will fuck him in this new frame for a few hundred. The currency is new but the conversation is familiar. But the poor bastard can't get off. He's haunted by the knowledge that the Gaul he lusted over is not just dead, not just buried, not just dust, not just forgotten, but that everyone she ever knew is also long forgotten, that the only record she ever existed is a memory in his/your head, vivid and solid and real today but maybe evaporating tomorrow with the morning mist. It's no surprise that no matter how convincingly that working girl puts on a show of orgasming on your borrowed cock, that legionary is just too overwhelmed by the flashbacks in your head to possibly let loose your seed.

Fucking sucks, man

[vpofcookies]

Technoblade assigned rocks/minerals based on vibes only:

(list below the cut)

Rubies, garnets, alexandrite

Ruby in zoisite

Amber, Honey calcite, citrine

Mahogany obsidian

Flint/chert

Smoky quartz, rose quartz

Cinnabar

Feldspar (especially k-feldspar)

Fire opal

Copper and gold

Emerald

Aragonite

bloodstone

Calcite (especially dogtooth and Icelandic spar)

Golden rutile quartz

Image Sources: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21

[astra-ravana]

Working With Fleurety

Demon Of Ice And Hail

Other names: Fleruty, Fleuruty

Other titles: Royal Scientist of Hell

Colors: Ice blue, blue, cyan, violet, white, silver

Herbs: Oak, pine, valerian, mugwort, thyme, yarrow, chives, tarragon, lovage, sorrel, mint, sage, skullcap, ginger, cinnamon, nutmeg, chaga, bear berry, dandelion root, myyrh, dragon's blood

Crystals: Iceland spar (optical calcite), angelite, blie calcite, celestite, chalcedony, moonstone, pearl, opal, tanzanite, selenite, scolecite, phenacite, dumortierite, blue aragonite, apophyllite, blue lace agate, herkimer diamond

Element: Water/air (ice)

Planet: Neptune, Uranus, Pluto

Zodiac: Pisces (Aquarius)

Metal: Silver, steel, platinum

Tarot: Death, the Tower, the Hanged Man

Day: Wednesday

Animals: Polar bears, leaopard seals, snow leopards

Domains: Hail, snow storms, ice, binding magick, science, research, experimentation, necromancy, survival, combat, conflict, nighttime activity, dream work, third eye vision, illusion, glamour magick, enchantment, transformation, spiritual alchemy, mental manipulation, chronokinesis, dark nights of the soul, shadow work

Offerings: Fresh snow/hail, ice sculptures, winter blooming plants, alcohol, meat, berries, nuts, roots, blood, milk and honey, items found in nature, knives/axes/arrow heads, outdoor tools, scientific instruments, books and knowledge, moons and stars

Sigils:

[california27]