Where does this come from, and can I check it?

Birefringent minerals refract light at two different angles based on polarisation. The figure is taken from USGS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a science fact?

Yes. It sits on the Science shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Calcite crystals split passing light rays into double images

Birefringent minerals refract light at two different angles based on polarisation

Calcite displays optical birefringence, a property where a mineral's crystal structure causes incoming light to split into two separate polarised rays traveling at different velocities. Looking through a clear optical calcite crystal reveals double images of underlying text or objects. Polarising filters use this double refraction phenomenon to control light wave orientations.

Calcite-251002 photograph — Robert M. Lavinsky · CC BY-SA 3.0 · licence · source

Where this comes from

USGS

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

Go further

Science trivia Unit Converter

More facts like this

Optical fibres trap light using total internal reflectionLight signals bounce inside glass cores without escaping through the outer boundary Light bends when transitioning between different transparent materialsRefraction alters the direction of light waves due to changes in propagation speed Quantum dots emit vivid colours determined purely by physical sizeNanometer sized semiconductor particles tune emission light wavelengths by particle radius Graphene conducts thermal energy faster than diamondStrong carbon covalent bonds transmit acoustic heat phonons with minimal scattering Aerogel is a solid synthetic material that is mostly airReplacing liquid in a gel with gas creates ultra-light solids up to 99 percent air Graphene is a single atom layer of extraordinary strengthCarbon atoms bonded in a two-dimensional honeycomb sheet are two hundred times stronger than steel

Tags: materials, optics, calcite

Calcite crystals split passing light rays into double images: the short answers

Where does this come from, and can I check it?: Birefringent minerals refract light at two different angles based on polarisation. The figure is taken from USGS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a science fact?: Yes. It sits on the Science shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.