# The discovery of crystals with two axes of double refraction, and many of the laws of their phenomena, including the connection between optical structure and crystalline forms ;

# Not depositing crystals on paper, i. e. not easily seen in glancing light.

# Underlying areas of cholesterol crystals

# REDIRECT Ice crystals

# High Flux: high intensity photon beam allows rapid experiments or use of weakly scattering crystals.

# Gas hydrate crystals centrifuge method.

# Agglomerated wet coffee granules are rapidly frozen ( slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules ).

# liquid crystals

# colloidal crystals

# It can be produced in large crystals, yielding good efficiency, and

# Drop the Apple-At the Smithsonian, we learn of electric crystals that help Pierre and Marie Curie discover what they call radium, and then Langevin uses the piezo-electric crystal to develop sonar that helps save liberty ships ( from German U-boats ) put together with welding techniques using acetylene made with carbon arcs, also working the arc lights with clockwork regulators built by Foucault, whose pendulum helps him to take pictures of solar eclipses.

Few would dispute the verdict of James D. Forbes, an editor of the eighth edition of the Encyclopædia Britannica: " His scientific glory is different in kind from that of Young and Fresnel ; but the discoverer of the law of polarization of biaxial crystals, of optical mineralogy, and of double refraction by compression, will always occupy a foremost rank in the intellectual history of the age.

However, some liquid crystals are biaxial nematics, meaning that in addition to orienting their long axis, they also orient along a secondary axis.