Mineral Family: Tectosilicates

Chemical Composition: SiO2
Cleavage: None
Color: All colors, often multicolored and spotted
Crystal System: Hexagonal/trigonal
Gravity: 2.7
Form/Habit: Cryptocrystalline 
Fracture: Conchoidal
Hardness: 7
Luminescence: None
Luster: Vitreous/earthy
Streak: White
Transparency: Opaque

Jasper Placeholder
Jasper

Where does Jasper come from?

Jasper is found throughout the world.  Here are a few of the deposits of interest for the metaphysical and collectors’ market:

  • Bloodstone – India
  • Desert Jasper / Polychrome Jasper – Madagascar
  • Mookaite Jasper – Australia
  • Picture Jasper – Namibia
  • Picasso Jasper – Peru
  • Red Jasper – Brazil, Peru, South Africa, and the United States
  • Yellow Jasper – Botswana

Many well known Jaspers, such as Ocean Jasper, are actually Rhyolites

What is Jasper?

True Jasper is a Silicate mineral. However, “jasper” is a term that is often used to describe any kind of spotted stone.  This includes many varieties of spotted igneous rocks, which may be called by marketing names such as Ocean Jasper or Rainforest Jasper.  From a geological point of view, only spotted microcrystline Quartz may be properly referred to as a Jasper.

Quartz is divided into two main groups, macrocrystalline and microcrystalline, all of which can be colorless or appear in every shade of the raimbow.  Macrocrystalline quartz has well-formed crystals that are large enough to be seen by the naked eye, for example, Amethyst or Clear Quartz.  Microcrystalline quartz has crystals so small they can only be seen through a microscope.  These are typically grouped together under the name Chalcedony, or it’s subcategories Agate and Jasper. Jasper is usually opaque.  It may be a solid color or have spots or other random markings.

How is Jasper formed?

Jasper is created in cavities in ancient lava rocks and other extrusive igneous rocks.  Following volcanic activity, magma and lava are slowly transformed into igneous rocks broken up with cracks, fissures, other hollows.  Jasper is formed long afterwards, when silica-bearing water permeates the rocks and begins to fill these crevices.  As the water flows, it picks up an assortment of other trace minerals which give Jasper its coloring and patterns.  If the trace minerals are microscopic, the Jasper will take on a uniform color, such as Red Jasper or Yellow Jasper, or it may take on a multicolored appearance such as Mookaite Jasper.  If the trace minerals are larger, able to be viewed with the named eye, the Jasper will be spotted, for example Brecciated Jasper.

How is Jasper mined?

Jasper is found all over the world but is usually not valuable enough to be the primary focus of any large-scale mining operation.  It is however commonly mined in tandem with other precious metals and minerals.  It is typically mined from primary deposits which still have their original relationship with the host rock.  It is often mined in small-scale artisanal mining environments.

Jasper Associates

Jasper are associated with all other quartz varieties.  They are also commonly associated with Calcite, Hematite, Opal, Petrified Wood, and Pyrite.  A rare variety, called Tiger Iron, is a combination of Red Jasper, Hematite and Gold Tigers Eye found only in Australia.  Another rare variety is found in Arizona which combines Red Jasper with Azurite, Chrysocolla, Malachite and Turquoise.

What’s the deal with all the Jasper names?

Jaspers have a variety of marketing names. The simplest names are merely the color, such as Red Jasper or Yellow Jasper.  Others indicate the location of the mining operating, for example Mookaite Jasper which is mined near the Mooka River in Western Australia.  Polychrome Jasper is multi-colored Jasper found anywhere in the world, while Desert Jasper is a particularly deposit of multi-colored Jasper found only in northwestern Madagascar.

Many of the fancier Jasper names are quite new, first mentioned in the late 20th or early 21st centuries.  Some of these are “true” Jaspers while others are just pretty spotted igneous rocks, for example attractive Rhyolites might be marketed as Leopardskin Jasper or Rainforest Jasper.  The most famous spotted Jasper doesn’t actually go by the name of Jasper.  Bloodstone is a dark green chalcedony with red spots that was named long before modern geology began sorting minerals into categories.