Calcite, the most common form of natural calcium carbonate (CaCO3), a widely distributed mineral known for the beautiful development and great variety of its crystals.
A wavefront is a surface over which an optical wave has a constant phase. For example, a wavefront could be the surface over which the wave has a maximum (the crest of a water wave, for example) or a minimum (the trough of the same wave) value. The shape of a wavefront is usually determined by the geometry of the source.
A wavefront is a line or surface, in the path of a wave motion, where all the displacements at any point have the same phase. A point source leads to circular wavefronts, at large distances from the source they are straight lines. wave is a method of transferring energy from one place to another without transferring matter. Mechanical waves are those that require a medium for their transfer and include water waves, sound waves and waves in stretched strings.