To ponder upon agate is to ponder upon the infinite. Well, maybe not, but its close, and at least it's a good way to "kick-start" this article. I've always been amazed at the extraordinary variety of this gemstone. Just when you thought you've seen it all, you'll come on one that gives you that surprise and once more you realize how vast is agate.
Pronounced AG-it, this hardy gemstone has been cut and polished for centuries. From Roman times and centuries before, people have made good use of it. Some of the reasons are its abundance, its toughness, its workability and, last but not least, it's beauty.
It makes great arrow and spearheads as well as beads, marbles, goblets and bowls. It was the stone of choice for engraved signet rings and carved stamps for the sealing of documents because hot wax doesn't like to stick to polished agate.
Around our area, here at Cold Lake, it is mostly found as small waxy-looking yellow translucent nodules, and people often think they've found Amber. However, Amber is very light (so light it floats in salt water) and feels like plastic when you pick it up. The largest piece of agate I have seen locally is about half the size of my fist and was found in the area around Pierceland, Saskatchewan. I keep it just as it is to preserve its uniqueness. It is probably half its original size since it has a small cavity on the side where it hadn't finished filling in, and there are the characteristic ring patterns surrounding the hole indicating it's only half there.
Two thousand years ago, or there-abouts, the Romans set up huge sandstone wheels in a mill-type arrangement on a stream at a place in Germany where fine agate was plentiful. Around this agate cutting industry, the little towns if Idar and Oberstien grew until, today the major industry of the area is the procuring and cutting of every type of gemstone in existence. Though some, with a small view of it, consider it a minor gemstone, agate has had a major impact on the economy of many areas of the world. At the present, it is experiencing a faster escalation of value than diamonds. Custom jewelers in high traffic areas are designing around it and setting it in 18Kt gold with diamonds and many other exotic gems. The reason seems to be that, more than ever before, people are recognizing it as a unique gem.'
Fairburn Agate
It is a tough gemstone, a member of the quartz family with a hardness of 7 in the Mohs 1 to 10 scale, but with the type of internal structure that eliminates the brittleness that quartz can have. It takes a perfect polish and, like Jade, can be carved into very fine detail. Because of this, the finest cameos are carved in agate. Agate sometimes forms in flat layers. The art of cameos started in ancient times because of this tendency. When the workman obtained an agate with flat brown and white layers he would carve down through the white layer to expose the brown layer for his background and then, by varying the depth of the translucent white layer, he could create scenes or faces with marvelous life-like qualities.
As I write, I am bombarded with all that I should say about agate and so, the best thing to do is get a bit more organized about this. I'll deal with its family first, then: color, its availability locally in the marketplace, its value, and, lastly I would like to describe some of the more famous types of this stone. Perhaps I will touch on ones that are rarer and so are nearly unknown.
It's hard to find a lapidary (stonecutter) who didn't start out their pursuit by cutting agate in one form or another. Most of the time agate can be had quite cheaply and will produce a nice gem that the wearer can be proud of. If one is careful and thorough in getting each stage of the grinding and smoothing done well when the final step is reached a beautiful polish will result.
The agate belongs to the branch of the Quartz family called Chalcedony. It is pronounced cal-SE-dony. There are a number of similar members such as Flint, Chert, Jasper, Sard, Sardonyx, Bloodstone, Carnelian, Onyx, Chrysoprase & Jaspilite. The division between many of these is a little smudged as they begin to overlap so we'll go on to deal with color in agate.
Flame Agate
Color is a broad topic in agate and of course, can be a very exciting one. Since agate is a material that owes its color to traces if different minerals becoming incorporated in the microscopic silica which is the building block of the agate, there is a possibility is could appear in any color. Silica also is, by the way, the building block for the modern computer.
I have seen agate as yellow as a canary with a few black markings to really set it off. I have some agate from Globe, Arizona (which was all worked out in the early '50's), as blue as turquoise. In the Mojave Desert there is a purplish tinged blue agate which they call appropriately, Mojave Blue, who's rate of appreciation has been far more rapid than that of diamonds. There is a rare sapphire blue agate from Africa and blue agate from Mexico. Of these, the Mexican is apparently less vibrant in color.
In the area of purple, I have five species of agate. One is Rodeo Purple Agate from near Esqueda, south of Rodeo in the state of Durango, Mexico, which is a beautiful lacey banded dark lavender with light lavender, white, grey and amber bands (registered trade name is Royal Aztec Purple). The next is Luna Agate from LaMojina near Terrenates, Chihuahua, Mexico, which consists of different shades of purple and lavender. It is marked by white spherical eye patterns scattered randomly through the pieces. Parcellus Agate from Mexico is a gorgeous agate filled with concentric line patterns (called fortification agate) of white, grey and now and again a superb purple banding. Fourthly, I have a very small amount of misty purple from Idaho. Lastly, I have a very rare agate labeled from an old collection I bought as Ojo Azul Agate. I only know it came from Mexico, but the specific locality or state I haven't an inkling. It is a rich reddish purple with a bit of grey and white decorating the edges of the slabs. I've never seen it mentioned in any catalogue of reference book and, I know that once I've sold it all, I could never find a source for it.
Coyamito Agate
We still haven't exhausted the topic of color in agate, so on our next meeting, we'll continue with our explorations of this fascinating gemstone.
Happy Trails!