Aussie Lapidary Forum

LAPIDARY => Gemstone Faceting => Topic started by: Bucket on June 05, 2012, 05:40:53 PM

Title: Faceting dark coloured smokey quartz
Post by: Bucket on June 05, 2012, 05:40:53 PM

Hi all,

I have acquired a very nice piece of smokey quartz from the Cairngorm Mountains in Scotland, the 'cairgorm stone' as the locals refer to it.  It is a very dark coffee colour and has no inclusions, however it is VERY dark and I'm somewhat concerned that when I facet it, it will still look black with no light return.  The piece is around 2 1/2 - 3 cms round (1 inch in old terms).

Can anyone help with advice or perhaps a shallow design with a very high light return.

My only other option, I think, would be to cut the single stone into two or three smaller ones, as the colour is so strong it would be OK to do something smaller.

Thanks in advance, Garry

Title: Re: Faceting dark coloured smokey quartz
Post by: Lord_Thunda on June 06, 2012, 12:01:59 AM

Hi Garry,  beers

The only Cairngorm I have is in an antique setting I bought on Ebay. I'll try to take some pics of it tomorrow but just looking at it now ... it does look a lil dark. I spose it depends on the rough basically the same as smoky quartz. I have some that ended up darker than the others.

Not being a facetor I'd still be tempted to keep it as a single stone. If you look at http://www.thistleandbroom.com/shopping/jewellery/cairngorm-moreinfo.htm (http://www.thistleandbroom.com/shopping/jewellery/cairngorm-moreinfo.htm)  it shows dark stones in silver setting.

http://hillshepherd.blogspot.com.au/2009/09/scotlands-gem-cairngorm.html (http://hillshepherd.blogspot.com.au/2009/09/scotlands-gem-cairngorm.html)  This shows rough Cairngorm in its natural beauty. As you can see, part of it is darker so I wouldn't be too concerned.

Bob  beers

Title: Re: Faceting dark coloured smokey quartz
Post by: Lord_Thunda on June 06, 2012, 03:18:19 PM

Pics are up for ya Garry  ;D

I tried to find Cairngorm rough when I was looking for it a while back but could only find things like this. Still very happy to get one tho.  ;D

Title: Re: Faceting dark coloured smokey quartz
Post by: REXL on June 06, 2012, 04:10:55 PM

Garry, the usual way to go with dark stones is to lower the crown facets by a couple of degrees and open the table out to at least 60%. This lets the maximun light into the stone. You will have to be careful to fiddle the girdle and table facets to fit.

REXL

Title: Re: Faceting dark coloured smokey quartz
Post by: Bucket on June 06, 2012, 04:16:10 PM

Thanks Bob, those antique pieces aren't yours are they? They look very nice and I see what you mean about the darkness, my piece could even go darker than those, it looks like black spinel when looking at it, it only reveals its colour when you hold it up to the light.  I agree that I'd rather keep it in one piece as well.  I've got a shallowish SRB cut that I may get away with using but I'll exhaust all avenues before I start, I may not be able to replace this piece.

REXL will have a look at that and see what I can do, that's similar advice I got from a couple of older members of my local club.

Thanks, Garry

Title: Re: Faceting dark coloured smokey quartz
Post by: Lord_Thunda on June 06, 2012, 05:13:58 PM

Yep Garry its mine  ;D Had to have a piece from the auld country  :-[

Its the same piece just back & front pics to show from both sides.