2nd of 3 posts about garnets

This week I’m starting with spessartite garnet, whose name comes from the Spessart Mountains in Bavaria, where it was discovered in the 1830’s. It was a rare gem until an important find was discovered in Namibia, Africa in the early 1990’s. Now, this garnet gets its delicious orange color from its manganese component, making it one of the few gems that owe its color to its composition rather than impurities. As an example, chromium is the impurity that makes rubies red and emeralds green! Fancy that, eh?

Mohs hardness – 7-7.5
Toughness – fair to good
Cleavage – indistinct
Stability to light – Stable

Next is pyrope, the garnet most of us are familiar with. The name is derived from the Greek word, “pyrōpós”; “pur” = fire and “ops” = eye, meaning fiery-eyed. Large deposits of this garnet were found in Central Europe (Bohemia) in the 1500’s, so they are also referred to as Bohemian garnets which were highly popular until the1800’s. Their popularity is still seen in today’s jewelry pieces, and because of its dark color, it goes well in men’s jewelry. Below is a beautiful Bohemian garnet hairpin from the Victorian era that Ales and Maria Herdlicka donated to the Smithsonian Institution in 1937. *dreamy sigh! *

antique-pyrope-hairpin

There is one pyrope that has an unusual and surprising locale…ant hills! Yes, you read that right! These tiny (less than a carat) garnets are found on and around ant hills, especially in Arizona. You see, as ants dig their intricate network of tunnels, they come across the gems. While they work around larger stones, the smaller ones get taken to the top and chucked outside. As rain falls, the stones get washed off and moved down the side of the hill where they are collected then sold in lots to lapidaries who cut them, then sell them to jewelers and collectors who will mount them into jewelry. Shown below are photos of ant hill garnets. Fun, eh? I knew you would think so!

Moh’s hardness – 6.5-7.5
Toughness – good
Cleavage – none
Stability to light – Stable

Last is the love-child of spessartite and pyrope; color change garnet. This garnet comes from different parts of the globe, but those mined in Norway can exhibit colors that can exceed that of alexandrite! Some of the best specimens come from Bekily in Southern Madagascar whose colors change from greenish-brown to red-pink. Unlike many gems that change color by simply changing the viewing angle, this garnet has the specific ability to show dramatic changes in colors (brown/gray, bronze, greens, blues, pinks, reds and purple) by viewing it under various lighting. To get the full effect of this fabulous gem, it should be viewed under various lights (incandescent, candle and fluorescent) and different times of the day.  Consider me officially in love!!!  It’s important to note that the photos you see are of the same gem…
Here’s a nifty YouTube video of color change garnet; copy and paste into your browser to watch the magic happen! https://www.youtube.com/watch?v=1TGPK_P4kPA

Color change garnet hardness – 7-7.5 on the Mohs scale
Toughness – good
Cleavage – none
Stability to light: Stable

Care: Garnets should not be exposed to sudden changes in temperature. Ultrasonic cleaners and steamers are not recommended. The best way to clean them is with a soft cloth or soft brush (if needed) with warm water and a mild soap. Rinse thoroughly with room-temperature water to make sure all soap is rinsed off. Although they are tough and durable, remember to protect them from hard blows and keep them away from other gems to prevent scratching.
That’s all for this week, I hope you enjoyed this post, and if you would like my list of references, please don’t hesitate to ask! Feel free to comment and ask questions and I will reply as quickly as I can! Thanks for taking time out of your day to read this and because I posted it so late in the week, look for the final post no later than Saturday, have a great day!

Happy Birthday, January babies!

Happy Birthday to those born in the month of January! If you’re wondering if this a re-post from last year’s one and *ahem* only, it is (more or less); however, I’m adding in some things that weren’t included in last year’s post. So please visit this page each week and read on over the remainder of the month! My goal is to give you enough history, lore, care and chemistry knowledge about your special gemstone to wow people at your next cocktail party – not to mention that you’ll be a straight-up smarty pants!:

For you who are born in the month of January, yours is the birthstone of garnet, a gem that draped the necks of the pharaohs of Egypt and was entombed with their mummified corpses.  In ancient Rome, signet rings were set with carved garnets that were used to stamp the wax that secured important documents.  During the middle-ages, Garnets were considered cures against depression and protection against bad dreams. It’s also said that the Greek philosopher Plato had his portrait engraved into a Garnet by a Roman engraver!

Garnet is a group that shares the same crystal structure (think “family”).  However, the slightest diversity in their compositions (individuals within the family) will create a variety of colors; for example, Almandine Garnet (which will be talked about in this post) and Spessartite Garnet both share aluminum silicate as 2 parts of their chemical structure, but what separates them is their 3rd element; the iron in Almandine gives it colors that range from brownish red to blackish red, whereas Spessartite’s 3rd element of manganese delivers its (yummy) orange color.

When thinking about garnets, the color most people are familiar with is red, but as you can see from photo #1 (above) Garnets come in a fabulous color assortment, so…. if red garnets aren’t your thing, I’m certain you can find the color that suits your fancy! Not all colors will be discussed in over these 3 weeks, but I will cover as much as I can! As the different Garnets are discussed, I will post photos of the gems in their rough and faceted states *happy sigh!*, so you know how your birthstone looks both ways! You never know, you may start to fall in love with gems in their rough state! Just for fun, I will also include the gems in a jewelry setting…you’re welcome 😉

First up, is Almandine garnet, whose name is derived from the ancient Carian city of Alabanda (modern Doğanyur) in Turkey.  almandine-garnet-03102012-2-1

 

While there is a vast amount of this gemstone that is mined, only a small percentage is considered gemstone quality.  Like the red coloring of Pyrope, its differences are that it’s a bit heavier and darker; with its coloring ranging from brownish red to blackish red as mentioned above.

johnbetts-fineminerals-com

almandine_garnet_welcome

Almandine’s Gemological properties:

Moh’s scale hardness – 6.5-7.5

Toughness – Fair to good, they are durable for all styles of jewelry, but should not be subjected to rough wear or hard blows.  (That goes for ALL your jewelry, y’all!)

Cleavage – Indistinct or none (my research turned up both)

Stability – Stable to light exposure; do not steam clean them as extreme heat or extreme temperature fluctuations can cause the gem to fracture.  Exposure to harsh chemicals can cause corrosion.

Care: While you can use an Ultrasonic cleaner, always take caution while doing so.  The best way to clean them is with a soft cloth or soft brush (if needed) with warm water and a mild soap.  Rinse thoroughly with room-temperature or warm water to make sure all soap is rinsed off.

That’s all for this week, I hope you enjoyed this post, and if you would like my list of references, please don’t hesitate to ask!  Feel free to comment and ask questions and I will reply as quickly as I can!  Thanks for taking time out of your day to read this and I’ll see you next week, have a great weekend!

 

Some basics about Gemstones

Hello and Happy 2017 from your friends at Kaduka!  My apologies for being away so long and not keeping up with all the wonderful Birthstones, but I’m back and will do my utmost to keep up with this blog!

As I was reviewing my blog from last year, I was initially tempted to spread out January’s re-post over the entire month (thanks for the suggestion, Nancy D!), but as I was going over it, the thought occurred that it may be best to start off with information on 3 measurements of gemstone durability you may find useful; hardness, toughness and stability.  The information will (hopefully) tell you how to best care for your pieces that comprise your collection of lovely jewelry and I promise to do my best to include this information as I discuss the gemstones for each month moving forward!

First, let’s talk about the hardness of gems.  Based on the Mohs scale (developed in 1812 by German mineralogist Friedrich Mohs who tested 10 readily available materials), gemstones and minerals have a hardness (scratch resistance) rating that ranges from 1-10.  I believe that I can safely say that we’ve all heard that Diamonds (10 on the Mohs scale) are the hardest.   However, the “hardness” of the Diamond isn’t equal to its “toughness”.  This is because of its perfect “cleavage” which can cause it to break cleanly apart across certain planes (think how easily wood is split across its grain).

A “tough” gem is one that can withstand getting smacked around and still come up looking good (kind of like James Bond).  One such gem is Nephrite Jade, whose interlocking crystal structure makes it a good gem for everyday wear, even though it’s 6-6.5 on the Mohs scale.  Nephrite jade, in addition to quartz (and its varieties) Sapphire, Ruby and Jasper have no cleavage.

Just an FYI…I don’t want to cause any upset with the information about cleavage.  The highest concern about it is when the Gem is cut, polished and set.  Gem cutters are highly knowledgeable when it comes to cutting gems with cleavage and jewelers are experts in mounting your gem in a protective setting.

Finally, there’s the stability of Gemstones, which means that alterations to them can occur when they are exposed to various elements such as chemicals, heat, and light.  Gemstones such as Aquamarine (March’s birthstone) and Peridot (August’s birthstone) shouldn’t be exposed to acid.  Other stones, such as yellow-brown topaz can fade when it’s exposed to direct light for lengthy periods.  Opals (October’s birthstone) have high water content so they can crack from dehydration.

I didn’t want to overwhelm you with lots of information, so I hope the information I provided will give you an insight to the care of your jewelry.  If you would like a list of my references, please don’t hesitate to make a request!

Thanks for reading this, and look for my upcoming installment next week!

Cheers!

Kaduka

Image from Manikanta Impex