Sunday, November 21, 2010

Quartz (Quartz & Chalcedony)

Chalcedony & Jasper

Smokey/Citrine Quartz

"Yellow" Jasper

Quartz is a group of minerals consisting of the "Quartz" species and the "Chalcedony" species.  Quartz Rock Crystal is basically colorless, or clear quartz.  The Quartz species has many varieties, however, because it is not only based on color.  It includes species of Quartz that are Macrocrystalline, meaning that it is made up of crystals recognizable to the naked eye.   The varieties of Quartz Rock Crystal include Smoky Quartz, Citrine, Amythest, Tiger's Eye, and more.

Quarts Cluster with mineral outer layer 
Click on Pictures to Enlarge:
Assorted "dry unpolished" agate
Assorted "dry unpolished" agate

Chalcedony is the other species belonging to the Quartz group.  It consists of cryptocrystalline Quartz, meaning that it is made up of crystals that are microscopic.  There are many varieties (and subspecies?) of Chalcedony, including Agate, Jasper, Carnelian, Bloodstone, Petrified Wood, and more.  The blue variety of Chalcedony is only considered to be "true" Chalcedony by name alone.  I believe I have seen it being sold as "Blue Lace Agate", and "Crazy Lace Agate".


Sunday, October 24, 2010

Corundum (a.k.a. Sapphires and Rubies)

The minerals in the following pictures were soaked in vinegar, then scrubbed with water and baking soda.  The first picture of the vibrant blue sapphire has not been cleaned with anything.

Corundum is the mineral group that Sapphires and Rubies belong to.  A ruby is red corundum, and sapphire is every other color of gem quality corundum.  The blue variety of sapphire is called sapphire, while the other colors (except red!) are referred to as "fancy colored sapphires".  Light red and pink corundum are also sapphires, not rubies.  For industrial use, corundum is also used as an abrasive called emery.  

Parti-colored and Chatoyancy or Asterism
Because of their popularity and value, there have been many schemes involving enhancement treatment of the gemstone to get either more weight and/or better color quality from naturally poor quality gemstones.  I don't want to talk to much about that right now.  Sometime this winter I plan on publishing a post to this blog explaining some of the processes involved in enhancing corundum for the gem market, including the ethical heat treatment of gemstones, as well as such scams as laser drilling holes in diamonds and rubies, which are then filled with glass.  Buyer beware!

Most of the sapphires I've found are purple, or as a lot of people say, lavender.  Some are parti-colored (multi-colored), and I am certain that some are going to be star sapphires.   With only my 10x loupe, and without being able to polish them, I have been able to confirm the rutile needle inclusions that make the asterism (star) effect in one of the stones, however; I am certain more will display this after being polished.  I am also not ruling out the phenomenon known as "color change", meaning that in daylight, they are one color, and then under incandescent light they change a different color.  It is not common, but so far these rough stones are possible candidates.  

Black Star Sapphires

I have also recently found a spot with "black star sapphires".  If you do a search on the internet for "black star sapphire", you will see some awesome looking gemstones.  The "star", also known as "asterism" is caused by parallel rutile needle inclusions running in 3 different directions.  Black Star Sapphires can exhibit 6 and 12 ray stars, also referred to as "arms".

This one has really got me asking questions.  Is it a pseudomorph?  It also appears to have both pinkish purple and blue colors.

Monday, September 20, 2010

Garnets (just a taste!)

I've been told by locals this is one of the finest Garnets gotten out of the top few inches of sand on this river beach.  Of course it has yet to be cut and polished.  These loose garnets have come a long way down the mountain, and I have yet to make the trek upward.  I have been told bigger ones are at a higher elevation, but that will wait for my next trip.  I literally collected all the garnets you see on this page either on top of the ground or within a few inches underneath.  The loose garnets in the picture were found the way you see them.  I am told that the whitish or cream coloration you see on the outside of most of these specimens is calcite.  I need to confirm that, though.

After tumbling down the mountain side and breaking out of the host rock from erosion or from the impact of other boulders, most of these garnets do have stress fractures.  A few of them look as though they may become decent gemstones. The top row of bigger "rocks" are garnets still stuck in matrix.  The rest are loose and need to be cleaned & polished.  Like I said, though, there are probably only a small percentage of them that will make nice gemstones, unless of course they are star garnets.

Like I said, I do not have my testing equipment yet, but as of yet I will say that the majority of these garnets appear to be Almandine Garnets (also known as Almandite).

Garnets in Granite and Mica Schist boulder!

Gemstones are classified by Group, then Species within a group, then varieties of a species.  Garnets can be quite complicated.  For instance, Rhodolite garnet is a "transition" garnet between Almandine garnet and Pyrope garnet.  In case I've already started to lose you, here is a list of garnets in the garnet group:

Almandine: Dark red
Rhodolite (Almandine/Pyrope): Purplish red
Pyrope: Medium red
Malaya (Pyrope/Spessartite): Blue, green, & color change
Spessartite: Orangy red
Grossularite: Varies in color
Andradite: Green
Uvarorite: Green

Although some garnets may be the same color, the chemical composition and inclusions may vary slightly, thus creating a different species or "transitional" variety.  Feel free to ask questions about this.  There are many books and websites that explain the Garnet Universe in it's entirety.  
Spessartite Garnet (I'm pretty positive) - notice the different host rock or matrix?  This actually came from about 50 miles away from the above garnets.

Where I am prospecting many people not only mistake garnets for rubies, but even insist a ruby is a dark super transparent red garnet and everything else is, well, a garnet.  So many amateur prospectors and gem collectors believe this here, that I feel it important to say this.  A Ruby is actually a red stone belonging to the Corundum group.  The Corundum group consists of Rubies (red corundum) and Sapphires (every other color of corundum).  Rubies and Sapphires are not Garnets, and Garnets are not Corundum.

Saturday, August 21, 2010

Epidote and Mica (just to name two!)

An Epidote vien.  Dammit Jim, I'm a gemologist, not a mineralogist!
Beside a small river and exposed partially from a road cut, there are small veins of Epidote.  At first the epidote looked like it had formed with garnet and quartz, but after doing some research, it could also be the red epidote "piemontite".  Epidote appears to be fairly common, but I have read that light yellowish green and reddish colors are more rare.  I have found small quantities of both those colors and "black" epidote.
The outer "layer" of this crystal has been severely eroded,
but you can still see the nice light green color.

Another attempt to capture beauty without proper camera skills.
This crystal is actually a more brilliant color of green.

A small Epidote crystal cluster.

Epidote crystal.
"Black" Epidote. 

"Black" Epidote.

Epidote has been included in the mythology of various cultures, including the Greeks, Norse, and Native Americans.  Metaphysically, it appears to be used for spiritual growth grounded in earth energies, and is thought to be an overall positive and balancing stone.
Epidote Twin.

Nothing like fresh mountain peppermint and sage to make prospecting for the epidote an uplifting and pleasurable experience.

I also found some mica of interesting color.  These pieces were picked up off the ground. There are very nice formations of mica "clusters" throughout the face of the rock.  Mica is one of the names for "Coyote" in the Sioux languages.  A trickster that creates a story out of our experiences and reflects them back to us in such a way to cause us to make sense of them.  Fitting for this highly reflective mineral.
A variety of Mica.

"Gold" Mica.

"Gold" Mica and "Black" Epidote in Matrix.
"Huh?" - Yes, it is blue, red, and purple.  I believe it is some form of lava rock ... aren't they all?!

Oh, I almost forgot ... the salmon were spawning ...

Friday, August 6, 2010

Prospecting Adventure (an introduction)

The Salmon River in Idaho, USA
My name is Michael Brandon, G. G. S.  I am certified as a Graduate of Gemological Sciences from the Texas Institute of Jewelry Technology - - my intention is to share information and continue to learn information about not just gems, minerals and the many opportunities they may provide;  but also to share the wonders and the rawness of the journeys that lead to that star sapphire, ruby ring, or sometimes just to witness the treasure of nature's beauty.  Ah, now there's a thought ...

I've spent this last spring and first half of the summer camping out in the "Gem State".   It was an unusually wet spring this year.  The creeks and river were flooding and at first I wasn't real sure where I should start to look for gems.  Don't get me wrong, I'd love to find some gold, too.  I talked to some people in the various towns and communities about places that would be good to look for gems and tried to figure out what exactly could be found.  For the most part, people have been encouraging and informative.
Purple (possibly "Star") Sapphires from my first "dig".

Now that the rains have died down I have been digging, with permission, in the tailing piles of an old gold mine and at various other places within an hour's drive of where I am located.  I do not have my lab equipment for identifying gems and minerals yet, so I have found interesting specimens of as yet unknown identity.  Most of the specimens are simply found on top of the ground.  I was told that a lot of prospectors who have come through this region were only looking for gold, or just didn't know what the other minerals and gems were.  I have found  small pieces of "golden", pink, blue, purple, and star sapphire; a variety of garnets, serpentine, calcite, a nice piece of jasper, blue chalcedony, small and large clear quartz points, and a quartz point that appears to turn from smoky to citrine.   I have also found nice specimens of mica and other as yet unidentified minerals.  Later, when I have tested everything, I will update the unidentified minerals with their proper identification.
Blue/Pink/Purple/"Golden" Corundum.  Yay! Starting to get a little bigger!
Beautiful vibrant blue sapphire "chip"
Purplish pink sapphire
Vibrant pink sapphire chip

One great thing I have learned about prospecting is that when you are on your hands and knees in the dirt you begin to notice many different things besides rocks.  I have enjoyed learning the characteristics of certain insects and animals.  I have started to learn more about edible and medicinal plants since I have started camping and hiking more.  My conversations at the coffee shop have started to turn into mineralogy and mining study groups.  I finally figured out how to harvest some nice morel mushrooms.  Well, you get the picture.
A small Butterfly colony
Interesting Mushrooms with strawberries

I'm deepening my knowledge about indicator minerals for gemstones as well as geological formations and interactions.  There are limestone, granite, and basalt coming together in many places here.   I am collecting micro mineral specimens, and will be putting together some kind of website for my mineral collection in the future.  I am also interested in faceting and lab work.

You never know what I may be able to "gather" for you.  One thing I have learned, is that only reported minerals of specific locations are researchable through non-local resources.  In other words, not all found minerals have been reported to the government or mineral societies.

The first few posts in this blog may be a "catch up" of some of my recent prospecting adventures.