PARGASITE: TUCSON GEMS SHOW REPORTS: WHOLESALE

The big event of the day was traveling south to the wholesale shows in south Tucson.  Most venues seem clustered around the Holiday Inn and the Kino Shows and are in the extra-large “tents.” Inside each tent the numbers of booths and tables are almost overwhelming.  Vendors are selling a wide variety of jewelry, beads, rings, cabs—you name it.  We toured through several of the tents and the displays seemed identical.  I could almost believe that the different rings etc. were all manufactured in the same factory.  I also could not observe prices that appeared to be “wholesale” in nature.  Most of the gems, cabs, silver pieces had lower prices at other venues scattered around town--or so it seemed.  So, off we went to one of my favorite shows, the 22^nd St. venue. 

 

Lots of beads.

Silver of all sorts, shapes and prices.  A great variety of chains.

From semi-precious to the big boys: rubies, diamonds, sapphires, tanzanite, etc.

Rings for everyone.  Amethyst and red garnets seemed a good buy.

I wandered through the displays back to the table featuring Pakistani minerals where previously I had purchased ruby and spinel.  I had remembered the dealer also had a green mineral for sale that was nicely perched on a white marble—similar to the ruby and spinel.  However, I would need my best negotiating skills since this green mineral was originally priced at over my $5 minimum!

I was able to purchase the mineral, pargasite, a sodium, calcium, magnesium, aluminum silicate that is a member of the amphibole/hornblende group.  The chemical formula is one that would confuse a beginning mineralogy student: [NaCa₂(Mg₄Al)Al₂Si₆O₂₂(OH)₂].  As I understand the situation, pargasite is not only a mineral but part of a “group” bearing its name. Chromio-pargasite has chromium substituting for the aluminum; in ferro-pargasite iron replaces the magnesium, fluoro-pargasite has fluorine replacing the part of hydroxyl radical, potassic-pargasite has potassium replacing the sodium. 

 

I really liked this electric green variety of pargasite from Pakistan.  The translucent specimens are fairly expensive but like the previously purchased ruby and spinel, parasgite is a colorful metamorphic mineral perched on the snow white marble.  Length pargasite ~1.0 cm.

Like most hornblende group minerals pargasite occurs as opaque, dark green to green brown, prismatic to columnar crystals with a hardness of 5-6 (Mohs).  It has a vitreous to subvitreous luster and the prismatic forms have that diamond shape cross section created by cleavage angles of ~56^o and ~124^o. 

However, there is a variety of pargasite that is an electric green color and gemmy and transparent and that is what I purchased.  This type of crystal stands out very nicely on white marble.  The specimen came from the Hunza Valley of Pakistan and was found in metamorphosed carbonate shelf limestones.