AbraCalc

Snell's Law: Air to Diamond at 30°

Light entering diamond (n = 2.42) from air at 30° refracts to just about 11.93°, showing diamond's extreme bending power.

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How to use this tool

  1. Enter refractive index n₁, angle of incidence θ₁ and refractive index n₂ in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your angle of refraction θ₂ and the full breakdown beneath it.

Diamond's very high refractive index (2.42) bends light dramatically, which is the key to its brilliant sparkle.

Frequently asked questions

What is total internal reflection?
When light in a denser medium (e.g. glass) hits the boundary at an angle greater than the critical angle, all light is reflected back. This is the principle behind fibre-optic cables.
What are common refractive indices?
Vacuum/air: 1.0, water: 1.33, crown glass: 1.52, diamond: 2.42.