Does colour banding affect cutting?

[Fullerton]

I have a fair bit of amethyst and a few other bits of gem rough with colour banding and wondered if/how this affects faceting?  I've noticed several websites which sell gem rough will infer colour banding as a negative .... although I would have thought the colour banding added interest to the stone. 

As a non-faceter I have have no idea on this one.  Any thoughts?

Cheers,
Fullerton 

[Aussie Sapphire]

As a non-cutter as well, I will defer to others more experienced.  However, it is my understanding that because amethyst is quite common in large sizes so stones need to be very clean for maximum value - the high presence of synthetic stones in the market adds to this pressure for maximum clarity.  As a commercial stone used in consumer jewellery at the budget end of price range, they need to be very consistent in colour and type so another pressure for stones to be very clean.

I dont think it physically affects how they cut - others may have a different opinion but pretty sure it is not an issue.  I would think this zoned or stripy material could be cut into really nice, interesting gemstones but I guess the market for these types of gems is much smaller.

cheers
Leah

[fossickeract]

    Depends ! As a hobby cutter rather than commercial I like to experiment. Banding will can be made to disappear from above if a brilliant or barion type cut is used and the desirable colour band is placed where all the light passes through it(the culet mostly). The whole stone takes on the desirable colour. I have a dog tooth sapphire which was mostly clear but with small blue band on the tip, putting that in the culet resulted in a royal blue stone. On the other hand a bright yellow with just a couple of blue bands across the axis( only visible with 10x) turned out a dull merky green. Banded stones can be cut with emerald cuts, or opposed bars to give great effects especially tourmaline and command higher prices.
     If you found it and cut it banding can make it distinctive and special, a stone for a collector but maybe not commercial decoration for a bimbo .
                                                        Ted

[Aussie Sapphire]

 If you found it and cut it banding can make it distinctive and special, a stone for a collector but maybe not commercial decoration for a bimbo .
                                                        Ted

You never know, the bimbo might quite like to wear stuff like that but in our experience of the jewellery trade, the companies making jewellery for "bimbo's" just want to churn it out and dont have time or patience to muck around with anything complicated (read beautiful but unusual).

We talked with a few manufacturers about using our (or at least other Australian) sapphire in jewellery - but for the mass-produced ranges, they were very open about the fact that the black sapphire was easier for them.  It was not as pretty but every piece was the same and they could turn out thousands.  The nice stones were really not much more expensive but they were not interested if they were not all EXACTLY the same.

I imagine it is much the same for the jewellery staples - amethyst, garnet, peridot, topaz.

cheers
leah

[calxoddity]

I was showing a colleague at work some of the sapphires we'd found, and much to my surprise she asked whether they were for sale and how much did I want for some of them.

 I was surprised because they weren't that big or anything, so asked her why she wanted to buy them, as opposed to buying from a store.  She said it was because they were different and not all the same, plus they were natural rather than synthetic.  I declined the request, but it established that there's a niche market for stuff that isn't mass-produced. 

Since then, two other people have also asked to buy some of my cut sapphires (but alas none of my raw rubbish!!!), for the same reasons.  The answer is still no, but if every I decide to buy some more camera goodies, I may reconsider...

Regards,
Shane

[Aussie Sapphire]

It is funny that way.

Whenever we had trays of sapphires at Minerama or a show, more often than not, people would pick out the partis or more interesting colours rather than the stones that were technically more valuable.

The industry has an idea of what is the "best" and therefore what is most valuable and when selling wholesale, you have to work that on that basis.  Often it is a very different idea to the people actually buying the goods.  They usually dont get ready access to that type of material unless they do go to a gem show - this stuff just isnt in the normal jewellery shops.

cheers
Leah

[mehoose]

In a nut shell yes...for all the above mentioned reasons.
What I will expand on is that there is an growing desire for natural, unique gems Worldwide. There is a definite market. In saying that you can't just get whatever it is and polish it. It still has to be visually pleasing. Whether that's freeform facet, freeform cab or custom facet or standard cabs, they still have to have the IT factor. Clarity, banding, even included gems all have their admirers/buyers. Granted there's not as many per mile as those who just want to buy something pretty, cheap, mass produced and off the shelf. The artisan jeweller/beader/wire wrapper numbers are growing as too are those into gemology and collecting.
I've seen too many gems, our Yowah and Koroit as prime example, where someone has just grabbed a chunk, given a very rudimentary polish on a butt ugly (IMO) shape and charging the earth, quite often getting it. AND or the same opal with absolute gem properties, with a hole bung through it,...sorry, starting to rant.
Look, gems in the rough untouched can scream absolute class, it's what you do with it or don't do with it to promote it's beauty that counts....set or unset.

(Yes I know, everyone has different tastes, that's the way it should be) ps. sorry Fullerton for being a wee bit vocal. 

[REXL]

I have cut plenty of banded stuff and no it does not affect the facetting. Is the amethyst banded with clear or yellow, if it's yellow then you have ametrine.
  If you cut as rectangles (a smiths bar is good) and place the bands you can end up with with basically a colour change stone as the bands tend to show when the stone is rotated.
REX

[Fullerton]

Some great & interesting replies so far ... and to think I'd hesitated and wondered whether this should have gone under the 'Ask a silly question' category.   

Anyway, it seems that banding doesn't affect faceting ... but ...may affect value.  I've always had the same opinion, as others have shared, that uniqueness has its own value.  A one of a kind stone cut to its full potential is always alluring.  I totally agree with Calxoddity's comments of there being a niche market for this.

I was mainly referring to stones with bands or 'waves' of colour through the stone .... I have amethyst with bands of clear and purple, amethyst with different bands of varying intensity purple and also smokey quartz with varying intensity bands of brown and perhaps golden yellow.  I'd also been interested in the cutting of chevron style material where there's alternating layers of amethyst, quartz and smokey which conforms to the crystal shape.

Cheers,
Fullerton

[mehoose]

LOL, Ok REX. It doesn't affect the faceting from how the stone is cut per se but maybe it would be better if I said how you orient/position the banding will have different visual outcomes.
Smith bar is a very clever design and yes, it looks great in both single and multicoloured stones.
Fullerton, are you talking more about the V shaped colours, Chevron?
Wonder how that would look if you positioned the point of the V down in the culet on a square or round? or..on an angle like they do with some of the schiller banded oregon sunstone? I've never tried this. I've just placed a deeper purple section in the pav like Ted suggested above but mine didn't have strong banding.
Is this making sense or a lot of gibberish and you want me to remove it?
LOL we posted tog.

[Fullerton]

Wasn't originally talking about chevrons but bands of colour (not chevron layers) through a stone.  The discussion, however, also sparked my interest in how chevrons might affect cutting also.

[mehoose]

Mmm, well obviously opaques/solids would be a moot point here but I thought you were talking more along the lines of patchy areas of colour and phantomy chevrony type stuff. The one you sent my way would be too dark I reckon for faceting as a faceted, through the light around inside the stone but there's nothing stopping you from having a faceted cab/tablet style opaque one.

I'll try and find you some nice pics to look at where the bands stand out. Have a look at some of the cut sapphires Andrew and Leah have on their web site.
I haven't cut anything with definite bands yet.

[mehoose]

Ok, here's one page that shows you a few different effects, schiller, bi colour, inclusions and how they have been cut to show. Still looking for a few more good ones.
There's Tourmaline, phosgenite, sapph, scapolite,

http://www.thegemtrader.com/NewItemsOct10%20-%20The%20Gem%20Trader.htm

Love this Zirc
http://www.thegemtrader.com/Sep%2007%20BZircon%20Page.htm
Interesting Creedite
http://www.thegemtrader.com/Sep%2007%20Creedite%20Page.htm

I'm still looking, will find one using phantomy chevrony things.

[Fullerton]

Some great examples there ... thanks Mehoose.

[mehoose]

YW, glad to see I got something right.  ( One of those days  )