# 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 ;

# biaxial crystals, and

# 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

# 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.

The large number of experiments exploring the physics and chemistry of these so-called " colloidal crystals " has emerged as a result of the relatively simple methods that have evolved in the last 20 years for preparing synthetic monodisperse colloids ( both polymer and mineral ) and, through various mechanisms, implementing and preserving their long-range order formation.

It deals with " programmable matter " ( like colloidal films, bulk crystals, and quantum dots ) that, he predicts, will someday be able mimic the properties of any natural atom, and ultimately also non-natural atoms.

To circumvent nanotechnological methods with their complex machinery, alternate approaches have been followed to grow photonic crystals as self-assembled structures from colloidal crystals.

For instance, a change of orientation of molecules as in liquid crystal displays, by interference and diffraction as in lustre pigments and holography, and by modifying the movement of light through materials by electrical means as in organic lasers, or in conjunction with light, opto-electronics, or by purely optical means photonics for instance by using photonic crystals made by colloidal synthesis and other methods.

DLVO theory is not effective in describing ordering processes such as the evolution of colloidal crystals in dilute dispersions with low salt concentrations.

It also can not explain the relation between the formation of colloidal crystals and salt concentrations.