Amazonite is a potassium-based feldspar, similar to the igneous mineral microcline. The source of amazonite's green color is surprisingly complex, possibly coming from water and lead, rubidium, thallium, divalent iron, or some combination of all of these. The earliest known samples of amazonite jewelry come from Middle Egypt and Mesopotamia, although it was not known as a distinct gemstone until the 1700s.
Handmade items vary in size, shape, and color when selected randomly (the highest quality items are chosen first). They'll be as beautiful as those in the photos.