BLUE CHALCEDONY (kal-sed-uh-nee) is a form of quartz consisting of compact submicroscopic fibrous crystal aggregates. The natural blue color is attributed to interference of light caused by voids between the individual crystals.......a phenomenon known as "SCATTERING". The color ranges from a very light to a fairly rich blue, and clarity from nearly transparent to nearly opaque.
The terms, chalcedony and agate, in practice, are often used interchangeably......the latter simply being the result of successive depositions of the former.
Blue chalcedony is composed of compact masses of tiny quartz crystals and the size of these crystals can vary, as can the amount of spacing between crystals. As a result, properties such as hardness, and reaction to light and coloring agents can and usually will differ in various specimens or within portions of the same specimen. This is particularly true of blue agate.... the layers of which can ,and usually do vary, in color, texture and transparency. Due to impurities, there are often brown, gray, white or colorless layers interspersed with and modifying the color of the blue layers. This is why proper selection of rough and savvy cutting is so essential to the creation of a fine gem.
It is perhaps worth mentioning here that while there are many similarities between samples from various sources, there are also distinctive, characteristic, differences. I personally feel very strongly about the need to disclose the origin of these stones in the course of commercial transactions. All sources have produced beautiful gems. Some varieties, such as the Ellensburg Blue, ( found sparsely scattered in vast alluvial gravels) are valued as much for their rarity as for their beauty. A premium is paid for fine gems from this source and that is as it should be. However every source of gems is finite. And every beautiful stone regardless of origin is a thing to be treasured.
Hardness---- 6 1/2 to 7
Specific gravity----- 2.60 (+ .10, -.05 )
Refractive Index----- 1.535 - 1.539
Cleavage----- none
We are very fortunate to live where one can still wander areas of the beautiful Kittitas Valley in search of gem-quality blue agate. We are justifiably proud of the local material.HOWEVER.... we do need to remind ourselves that ours is not the one and only "true" blue agate. All too often stones from other regions of the world are denigrated by local "experts" and treated as imposters or cheap fakes. This is unfortunate because many of these gems possess outstanding beauty and unique qualities of their own.It is also unfortunate that material from other sources is sometimes intentionally misrepresented so as to deceive prospective purchasers of supposedly local gems. This is NEVER an acceptable practice. It only serves to create unwarranted predjudice towards fine blue agate and chalcedony from elsewhere on the planet. PREMIER GEM DESIGN, has been cutting blue agate and chalcedony from numerous sources for over twenty years. We have never and will never intentionally misrepresent the origin of the stones we sell. We are proud of our ability to provide a wide selection of the very finest gem blue chalcedony from locations around the world.
