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Gems-What is Jasper

What is Jasper?

Jasper is an opaque, (not able to be seen through; not transparent)  variety of chalcedony.

Jasper contains enough impurities and foreign material to render it opaque

Microcrystalline quartz in its pure form is semitransparent. When a small amount of impurities or foreign materials are added, the colour of the microcrystalline quartz changes and its ability to transmit light decreases.


Jasper is derived from the Greek for “spotted stone”. Jasper is usually considered a chalcedony, but scientists put it in a group by itself because of its grainy structure. Finely grained, dense jasper contains up to twenty percent foreign materials that determine its colour, streak and appearance. Uniform jasper is rare; it is usually multi coloured, striped, spotted or flamed.

Chrysoprase, a bright apple green translucent chalcedony, is the most valued. Some treasured jasper stones exhibit a picture that appears to be taken from nature and are called “landscapes”. Another specialty is bloodstone or blood jasper, also known as “heliotrope”; a dark green chalcedony or jasper with flecks of red. Most jasper is opaque and takes an excellent polish. Jasper is used for ornamental objects, cabochons and stone mosaics. Care must be taken during cutting. Banded jasper tends to separate along the layers.

Real Difference.

The real difference between Jasper and Agate is the amount of impurities and foreign material contained with a specimen.  In other words the colours, found in Jasper are more because of the other minerals,, and can be very colourful. when polished. But you can not see through the Jasper Gemstone.

Agate has lots of colour also, but has a more dull crystal look. some of the colours you can see through, other you can not. Finding a agate you can see all the beautiful colours, when cutting them you find crystals I  the middle of some Agate Stones.

Agate is a form of chalcedony quartz that forms in concentric layers in a remarkable variety of colours and textures

Calcite. you can see through and can not see through it,  The orange broken  stone I have in my hand ,you can not see through it, but the stone I have that looks like a slab of crystal you can see through it, the Calcite stone is  shiner and is a cleaner stone, mostly one colour.

You can get a Jasper, Agate, and Calcite rock all the same colour.

Jasper is a variety of quartz with a chemical composition composed primarily of silicon dioxide. Up to 20% percent of fine dense jasper can be composed of foreign materials, typically Hematite, pyrolusite, clay or calcite.

Jasper has a microcrystalline structure which means its trigonal crystals can only be seen under high magnification. It can be easily distinguished from many other similar materials by its excellent hardness and lack of cleavage.

Identifying Jasper.

Jasper can be one colour or lots of different colours.  The picture in the image on top of the page is multicolour Jasper.

Images of Jasper Gemstone.



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