Thursday, May 31, 2012

Rock Review: Flourite

Flourite is named for the Latin "fluo"-- to flow,  because it is used as an additive to aid in proper flow for iron smelting. Additionally, the phenomenon "flourescence" takes it's name from this stone where strong flourescence can commonly be observed under UV light.
Excellent Specimens of flourite have beautiful, intense color banding in all shades of purple, mint green to teal, some pink and white. Strong color banding is a good way to identify flourite, but not all material is so fantastically banded. See below:
This is more common.

Flourite is found commonly cut into beads, and for other ornamental purposes. It can be found cut as a gemstone for setting in jewelry, but it is a relatively soft stone, making this practice uncommon.

This gem does have a common place in gemstone healing, however. It is thought to strengthen one's power of concentration. It is also used to cleanse the aura, and it is applied directly to an ailing part of the body to relieve pain.

Different colors of flourite are thought to have more specific benefits, more information on this here:

Thursday, May 24, 2012

Rock Review: Turitella Agate

Turitella Agate is a fossil gem. The creastures fossilized in Turitella agate are called Elimia tenera (erroneously considered Turritella) shells. Elimia tenera are spiral marine snails having elongated, spiral shells composed of many whorls.

A good cut of Turitella agate features a bounty of these beautiful shell cross sections. these gorgeous stones come from the Green River Formation in southwestern Wyoming, Northeastern Utah, and Northern Colorado. The material is found in layers deposited in ancient lakebeds formed over 40 million years ago.

The coloration is typically a mixture of black and brown tones with the fossilezed shell patterns appearing in shades of pearly white. to beige. Because of the fossil nature of the stone, these gems are considered to carry a memory and help the wearer with memory and looking into the past. 

Monday, May 7, 2012

Diamonds Part 4: CUT

The standardized grading of diamonds is a relatively recent industry development. Even after GIA established color and clarity grades, there continued to be a missing factor in a set of scientifically gathered information to accurately asses a diamond for quality. The final factor, thr fourth “C” stands for cut.

Color and clarity are inherent properties of the diamond as it comes out of the earth, yet the cut of the diamond is man's effort to unlock the shimmering beauty of the stone. Because diamonds are the hardest substance on earth, cutting a diamond in just the right was to create maximum brightness and fire is no small feat.

After my trip to GIA at the end of April, I have a profoundly new appreciation for the impact that a cutter can have on the overall look of a finished diamond. I analyzed some diamonds with excellent clarity and color grades that simply did not seem to sparkle. One in particular just looked dark and lifeless.

When I began to measure the proportions of the stone's depth as well as the angle and size of the facets, I discovered that while the gem looked similar to the other diamonds, it's proportions fell far outside of the prescribed ranges for excellent cutting. So even though this diamond was worth a great deal of money as rough material, the work of the cutter was of poor quality and really damaged the potential value of the stone. It would be very difficult to sell a diamond that just didn't seem to sparkle like the others.

On the other extreme, a diamond which is cut to fall within the many proportion standards for an excellent cut grade looks like it is radiating with it's own light source! The cut grade and proportions are based on the physics of light entering the diamond, then bouncing around at just the right angles to come back out the top of the stone for your viewing pleasure. The more the light bounces around inside the stone, the more it “disperses” or separates into different colors of the light spectrum creating what is termed “fire” or the presence of different colors of light.