This an Amethyst from Guerrero, Mexico. Amethysts from Guerrero are known for their particular formation that you won't find anywhere else in the world. It has a long tapered crystal that will usually have secondary crystals forming a "sprouting" or "Kundalini" formation. The main crystal has several child crystals near the base of it as well as excellent color zoning with a very obvious phantom. The color gets more saturated the closer to the base you get.
This piece measures approximately 7.7cm x 2.0cm x 1.7cm and comes on an acrylic base measuring 3.5cm x 3.5cm.