Welcome to my August newsletter!

It is already the end of August (the last day!!) and it feels like fall is way too close. The leaves are already beginning to turn and flutter down from the trees. As beautiful as the colors may be, I'm not ready for it at all!

So, as long as I can, I'll enjoy the sights, sounds and smells of summer. I have a wonderfully generous daphne that blooms off and on all year. It's full of flowers right now that the butterflies are really enjoying, just as I am enjoying them!

Thank you to everyone who came to see me at one of my shows in early August. It was wonderful to see you! And a big welcome to new subscribers. I hope you enjoy this and future newsletters.

I want to let everyone know, if you didn't already, that you can read all of my past newsletters at Barbara Kay Jewelry Newsletters. Most issues have a featured stone, along with other information you may enjoy.

Barbara Kay Jewelry News

I am taking a little time off of making jewelry to re-charge my creativity after working hard to prepare for my summer shows. I don't have any more shows coming up until possibly early December - I'll post more information once I know for sure. I will be taking a lot of pictures over the next few weeks and will begin adding pieces to my Barbara Kay Jewelry shop during the first week of September. Consider a special one-of-a-kind piece of jewelry as you begin your Christmas shopping. Or maybe a gift for yourself! Check back weekly as there will be new pieces added each week.

Until the new ones arrive, here are just a few pendants that are currently available in the shop - click the image to see more pictures and read all about each piece:

And here are a few examples of the fun earrings that will begin finding their way into the shop this week. The top picture shows a few colorful bead and wire earrings; the bottom earrings feature a combination of metal-smithed components and beads. Perfect for gift giving and maybe even stocking stuffing!

Stone of the Month: Rhyolite

The last few stones I've featured have had bright colors, so I decided it was time for a stone that is a little more earthy and subtle. Hello, Rhyolite!

Rhyolite is a rock rather than a mineral, meaning it is made up of multiple minerals, including quartz and feldspar among others. It also usually has a high silica content. It can range in colors, as you can see in the picture above, but most rhyolite is pinkish, gray or cream, as seen in the picture below.

While a lot of the stones we've explored developed within the fissures and cracks caused by cooling magma, rhyolite is actually the magma itself, specifically a type called granite magma. Different types of volcanic activity will determine if this magma becomes granite or rhyolite.

Granite magma is rich in silica and also often contains a high percentage of gas. This combination can create highly explosive eruptions as well as effusive eruptions. The explosive eruptions create pumice and tuff, while the effusive eruptions, where the molten magma flows sluggishly rather than being flung into the air, produce rhyolite and obsidian. The cooling conditions and speed also help determine the final rock's composition. Both types of eruptions can occur at the same time, and all four types of rocks can be found after a single eruption.

These types of eruptions almost always occur on land rather than in the ocean. And they are apparently quite rare; since 1900 only three are known to have occurred - one each in Papua New Guinea, Alaska and Chile. This is a good thing, as these types of eruptions can be catastrophic.

Historically, rhyolite was not used for jewelry. However, it was used in prehistoric times to make tools and things like arrow and spear heads. Currently it is rarely used in manufacturing or construction, but is sometimes crushed for gravel. Landscapers sometimes use chunks of it - either natural or carved - it as yard decoration. But, thankfully for us, some rhyolite has now become popular as a semi-precious gemstone used in jewelry.

What has made many examples of rhyolite a fun stone for jewelry making is the fact that like other magma, little pockets and cracks occurred as the rock cooled. These are called 'vugs'. A variety of mineral rich fluids often found their way into these vugs and crystalized, becoming part of the rock. These minerals include agate, jasper, quartz, garnet, topaz and opal, among others.

Sometimes the magma cooled in bands with slightly different mineral composition creating beautiful layered patterns. You can see that in a few of the stones below. These stones are also called Dendritic Rhyolite, as they include inclusions called 'dendrites." These mossy looking dendrites were created when hot mineral rich fluids ran through very thin fractures or veins in the cooled magma and ultimately became part of the rhyolite stone. Many different stones include dendrites - I may do a feature story on dendritic stones of all types one of these days.

One thing I've discovered during my stone research is that trade names (names given by stone sellers) don't always reflect the actual identity of a stone. There are quite a number of rhyolite types that fall into this. Usually they are given a name with jasper in it. I'm not sure if that's because people are more familiar with the name jasper than they are with rhyolite, or if the people coming up with the name think jasper is a more desirable stone, but the jasper name ends up being what is most commonly used. Here are a few examples of that.

Rainforest Jasper is actually rhyolite, although it often does have jasper crystals mixed in, along with possibly agate and other minerals. It is also more green than many examples of rhyolite, which contributes to its name.

Leopardskin Jasper is another. You can see how it got its name!

Mushroom Jasper is one more. I am guessing there are even more out there that I don't know about... yet. Mushroom Jasper, or Rhyolite, is another one named for its appearance - don't those patterns look like the mushrooms you often see lining up on tree trunks?

I love this next one. This one, as far as I know, has the word rhyolite in its name, and once again, it has an appropriate name: Galaxy Rhyolite. I especially like the little square cabochons with the almost firework appearance. Of course they could be exploding novas as well!

I have one final example of rhyolite to show you that is a little different. Remember that I said opal was one of the minerals that could find its way into those rhyolite vugs? The Mexican Cantera Fire Opal is a perfect example. These are little fire opals embedded in rhyolite. When they are cut and polished, the rhyolite surrounding the opal is kept in place, creating a window effect into the glowing opal. Cantera translates to 'quarry', which refers to the rhyolite. Here's one example - it does not have as much opal fire as I'd like, but you can get an idea of what they look like.

Rhyolite is a very common stone, although most of it is not jewelry worthy. Since it is fairly common, it is not terribly expensive as gemstones go, although some of the really nicely patterned ones can be quite desirable.and thus more valuable. Of course, the ones that include gemstones like opal are also more valuable.

This fun and varied stone is found all over the world, especially in parts of Europe, Asia and the Americas. Nevada in the US actually has a town (now a ghost town) named Rhyolite due to the rhyolite deposits in the area. It only occurs in areas that have had extensive volcanic activity, of course. Those who live in the Pacific NW like I do might be interested to know that Crater Lake was formed by a rhyolite creating eruption.

As a gemstone used in jewelry, it is generally fairly hard, although it can be scratched by some of the harder gemstones or metals. It's a good idea to store all jewelry with stones separately for that reason. It can be cleaned with warm soapy water and a soft brush or cloth. I have read that it's best to keep rhyolite out of prolonged contact with water - that's really true for most stones.

I currently have two pendants that feature rhyolite. Funny enough, both are mushroom pendants. The one on the left is in the shop; the one on the right is not although I will get it in there soon:

I hope you enjoyed exploring this less well known stone. If there is a type of stone you'd like me to feature, please send me a quick email: bbureker@gmail.com. I am always looking for new ideas!

Many of the photographs used in this article were provided by Laurie Gates Engelhardt - thank you, Laurie!

I would love to hear from you. Let me know what you think, and what you’d like to see in future newsletters.

Sources used for the Rhyolite article:

Geology.com: Rhyolite - https://geology.com/rocks/rhyolite.shtml​

Rock&Gem: Rhyolite Rock: Formation, Uses & Facts - https://www.rockngem.com/rhyolite-formation-uses-facts/​

Gem Rock Auctions: Rhyolite Gemstone: Properties, Meanings, Value & More - https://www.gemrockauctions.com/learn/a-z-of-gemstones/rhyolite​

Learning Geology: Rhyolite - https://geologylearn.blogspot.com/2015/03/rhyolite.html​