Of all sedimentary minerals, calcite is probably the most widespread, contributing a full 2 % to the volume of the Earths crust. It occurs in endless crystal forms with many different colors. With such variety it is not surprising that some collectors specialize on calcite alone.
Agate is a beautiful and very popular gemstone that is widely recognized for its unique and varied colors and banding. It is a type of microcrystalline quartz that is commonly used as an affordable alternative to pricey gemstones in jewelry. It may also be carved into figures or statues, or used in handles for knives.
Chalcopyrite is the most important copper ore, and it is the primary source of many popular secondary copper minerals. It can occur in a variety of environments and forms, from hydrothermal veins to sedimentary layers. Nice chalcopyrite crystals are highly sought after by collectors.
Galena, historically also named lead glance, is among the most abundant sulfides. Nice crystals and clusters of galena are almost every mineral collection. But this common mineral has some interesting features and it source for many beautiful secondary minerals.