Agates and Jaspers

These types of stones are forms of quartz. But while we know quartzes mainly as crystals — amethysts and citrines and the like — or from their "stuff-in-quartz" inclusions, agates and jaspers have crystals so tiny that they can't be seen as crystals. "Cryptocrystalline" quartz is the proper term. Agates and jaspers are part of the chalcedony group, and it's often difficult to tell them apart.

Here is what the experts say are the important differences between them.

1. Agates are formed in concentric rings.  There are arguments about WHY this is true.

2. Jaspers may be striped or include circles, curves or other patterns. They are rarely only one solid color.

3. Agates are more porous than jaspers.  Hence they are often dyed to produce striking colors.

4. A thin slice of agate may be translucent.  You can see light through it. This is never true of a jasper.

So...now that you know all this, the question is why you should care.  The real answer it that these factors help narrow your choices in a very large field. Each stone of either kind is truly unique.  In short, both the differences and the reason they are loved by most people as one-of-a-kind treasures is pattern, pattern, pattern. A distant second may be color.

Because agates and jaspers are widely distributed and relatively easy to find, they are (usually) rather inexpensive. Price and pattern make them truly striking "signature" pieces that can be obtained by anyone.