There are differences in the percentage of impurities. This makes stones like jasper opaque while the large crystals can be water clear. The microcrystalline structure produces microscopic crystals. Normal quartz crystals are large as in clear quartz, smoky quartz, rose quartz, and amethyst. All of these are also microcrystalline quartz minerals. Jasper is closely related to several other minerals: chalcedony, chrysoprase, nephrite, carnelian, and agate. Jasper and the microcrystalline quartz family Julia Davidian Jasper earrings $187, SHOP NOW. Manganese, for example, produces a blue color. The color of the stone is determined by the mineral composition of the area in which it formed. What color is jasper? It is mostly red, green, yellow, brown in color, and rarely blue. And because it is so common, except for a few rare varieties, the stones are inexpensive. Iron oxides cause the common red color.īecause of the wide varieties of colors and patterns and the excellent polish, jasper is valued for jewelry. Up to 20% of the stone can be impurities. The stone is an impure quartz with microcrystals of silicon dioxide (SiO2). This means that it polishes brilliantly and maintains its luster despite use. A variety of chalcedony, jasper has a hardness on the Mohs scale of 6.5 to 7.0. The name, jasper, comes from the Greek, meaning ‘spotted stone’. Jasper properties: Endless varieties in color and patterns Jasper is considered a stone of grounding and stability. It is opaque and mostly red, green, yellow, brown in color, and rarely blue. The jasper stone is a type of chalcedony that contains impurities like iron oxide and clay.