This citrine crystal is from Diamantina in Minas Gerais, Brazil. Citrine is the orange yellow variety of quartz. When a quartz crystal is pure it is colorless, transparent and only contains the elements Si and O. Trace amounts of other elements in the crystal lattice can change the quartz into a variety of colors. This is a natural, unheated and unpolished crystal. It is transparent and has a bright luster. It measures 1 3/4 x 1 1/8 x 3/4 inches or 44 x 28 x 19 mm.