Sphalerite

[Maxx]

My first time in this pages... Hi to all.. I'm Italian gem cutter. I was reading the old posts regarding sphalerite and... well I was collecting (and cutting) sphalerite since the 70's.... I'm really inloved in this material. I collect it since my first visit in Spain when i was younger....
I have had and still have some unique stones and rough, The material has N=2,37 (refraction index) very near to the diamond, and a dispersion index much higher. The hardness and the six direction cleavage axis really offer to the cutter a challenge each stone he is trying to facet.

My rough is thirty years old and more, unfortunately the mine was flowed and today only the speleologyst can reach the material with danger for their security (the acces to the mine was forbidden still in 2007... no have more recent news about).

I have faceted 50, 70, 100, carat gemstones, clean, with few inclusions and some eye clean 20- 30 carat gems.... these are betwen the masterpieces... and approximately one hundred of very very fine gems with some inclusions and faint color changes zones.

The sphalerite can have all the colors of the yellow: green, yellow green, yellow, yellow orange, orange, orange brown, brown red,
The rarest colors are the green and the red, but the best result in cutting it you have in the yellow-green colour, This variety is clear enough in order to maximize the dispersion effects, In this color you can get the rainbow in the reflected rays fron the culet and look at all the spectrum colors.

from this experience I begun to classify 12 grade of the cutted sphalerite depending from the color, the quantity and the type of inclusions, the way the ligth pass through, the size, the result of the cut.... In this way i have a method to judge a stone even if the reference stone is no more available or while the time passes. Each caracteristic has a parameter that can increase or decrease the base value.... I defined a base price per carat... this price can be rised by a connection of good caracteristics up to three times or lowered up to six time if these are penalizing.

my method gives to me prices around 40-60 euros per carat for the best stones... and 20-30 euros per carat for very nice stones.

Sorry for my english... I hope my experiance and my point of view will be helpful... if you will be interested I can post some images of my works.

ciao

 

[Pandora II]

Ciao Max!

Benvenuto a Pricescope - non preoccupare, il tuo inglese e quasi perfetto!

I would love to see some photos of your Sphalerite - it''s one of my favourite gemstones, but sadly way too soft and fragile to do much more than admire I think! Are yours collectors stones, or have people had any success with setting them at all?

I was looking at some nice ones in the Natural History Museum here in London a couple of weeks ago. They had a couple of yellow/greens and a red - the red was interesting but VERY included, so you didn''t get the real effect.

Is there any chance you''d be happy to share your knowlege on the 12 grades?

 

[Maxx]

Hi Pandora II, here you can look at a 90 carat sphalerite from an old rough I cutted last year

the green and the red specimens are usually more included than yellow-green and yellow orange colors.... but this only due to my experience of the Picos d'Europa origin material (this is the only material I own and cut).

I changed my icon avatar with the image of a 39 carat grade 11 (in my scale) sphalerite.. G11 means the stone has uniform color, no inclusions, good brilliance, good dispersion, no defect in the cut, a weight over 20 carats, with faint and smooth changes in the uniformity of the color inside, and cristalline clarity.

 

[Ninama]

Molto squisito! Come marmellata d''arance...

Excuse my Italian!

It''s beautiful, Maxx.

 

[Pandora II]

That''s very beautiful - I like the one in your avatar as well.

Sadly it''s another of those stones that are nearly impossible to capture the full effect in photographs!

 

[Maxx]

You are true .. it''s really difficult to get all details, the reflections and the "atmosphere" lying in a gem by a photograph!!

here you can see a 22 carat G12 gem. In the picture you loose almost all the rainbow effects due to dispersion, but it gives an idea.....

 

[Pandora II]

That is an amazing stone - I think you get a better idea of the effects from this picture than the others.

For those who have never seen a real live sphalerite, we are talking AMAZING fire - even better than Sphene, and a lot more than diamond.

I just wish it was about a 7 - 8 on the Mohs'' rather than a 3.5 - 4

The Picos d''Europa mine is the best place to get Sphalerite isn''t it?

 

[Maxx]

Yes Picos D'Europa is the historical best place, unfortunately the mines are been flowed twelve, fourteen years ago and are still closed and forbidden. Today no rough is coming out from the mines. The "new" gemstones can be cutted from old rough, or by sacrifying the crystals specimens in the collections

(don't do that please). The Chineese material i was able to see is always orange-red, red-brown and, in most cases, is not suitable to produce medium large clean gemstones.

In Barcelona, last year, I saw three very nice gemstones oval shaped around the 6-8 carats priced at 360 Euros

per carat (that means someone has loose his brain somewere!)

I cut, sell, collect and definitively..... love this material, it is rare and while the time passes more and more rare...it has extraordinary optical caracteristics, beautiful color, but........... it is fragile! You can't price it like a precious or semi precious stone suitable for jewelery............................
.....................................................even if my wife has a ring with a sphalerite setted on it

 

[Maxx]

hemm sorry the mines.... had been flooded.... ehhh my english!!