⭐ Show Us Your Cut Stones - Before And After Photos

[GallicProspector]

Cristinite is a kind of glass (artificial), and like glass, I guess it scratches easily, a bit like TV glass.

 

[Dughug]

Cristinite is essentially a glass made out of low grade chrysoprase by a company in Qld - Advanced Crystallisation Technology Pty Ltd.
RI is around 1.61, in an early article produced by the company they suggested that there is a slightly different RI for the different colours.

Cristinite was one of the stones that was required for the 2014 Gatton GEMBOREE. This helped get many cutters trying the material. Cristinite damages easily and is very susceptible to internal micro-shattering if you cut it on a coarse lap. This will lead to scratching and chipping when you come to polish.

My suggestion is to rough the material out on no less than a worn 600 then step upwards with your cutting laps removing a reasonable amount at each stage. This will help remove any sub-surface damage and help avoid many of the problems you will get olishing i.e. scratching & chipping.

It polishes on both diamond on alloy laps however my preference is cerium oxide on a composite lap. (You can use acrylic, old CD's or mylar film)

The material is cheap, takes a really brilliant polish and with lots of colour variants including bi-colour and colour change it's good to have a play with. Although nothing will beat what Mother Nature makes for us to find.

 

[ktmman]

That looks great Lefty, good to see some awesome local material looking it's best.
Hope to see many more now you have your machine.

 

[Lefty]

I'll try to remember to bring it to Lowmead next time we're both there Richard. I have a piece I found the other weekend on the dop now, it a different shade to the one above, it's a smokey purple with the purple in bands like sergeant stripes in a sapphire. I'll bring that bit of citrine I cabbed as well, it's an interesting look. I'd like to find a crystal with that vivid orange colour right through it instead of just in a little thin band.

Cheers

Thanks Dug and GP - glass eh? Well it was handy anyway, I tested my first non-round cut on it which didn't turn out to be as tricky as I'd heard.

 

[Kingsolomon]

Nice stone lefty .. Did you do the table with 0" or an adapter 45" . Just wondering how it goes at o" .

 

[Lefty]

I just cut it at 0 degrees Barney - do you think the 45 degree dop - which I don't have one of - is better? I've actually had a little trouble getting a perfectly level table, it's always worked out in the end but usually after a struggle. I'm doing the table of a garnet at the moment and I'm hoping that the polish does the trick since the tips of the mains are virtually touching - if I stuff this up I expect I'll have to re-cut the crown. Hopefully I don't stuff it up.

A co-worker asked me to show her my collection, I've put them out on the staffroom table - I know they're not perfect (though the little amethyst comes fairly close) but there's been a lot of oooing and ahhhing going on You can't see most imperfections by eye and even if you can you often have to know what it is you're looking at before you spot them.

While I accept that I'm going to keep making mistakes, the goal is perfection here! This is not a game where near enough is good enough - that's for my day job

 

[Lefty]

Just finished this one. It looks good but the finished product isn't what I had hoped for. This is a modified el dorado brilliant cut. 15mm topaz. Ill add the carat weight this afternoon.

The rough had a thick but very light blue zone running at 90 degrees to the table. Unfortunately I failed to spot a flaw in the crown that ended up penetrating the table so had to remove 16 facets from the top to bring the table height down enough take most of the flaw out. A small amount can still be seen at the 7 o'clock position in the photo. A very large table coupled with a few angle changes resulted in a lot of the color bleeding out of the crown sides instead of being reflected back into the stone and out through the table. As can be seen at the 2 o'clock position.

Anyway, this was a very difficult cut for me as I haven't had to deviate so far from the original design before. I also found that when using an old machine and old laps even the slightest bit of wear and tear can effect the accuracy hugely. It would appear over time the play in the joints and locks for the head has made it a bit more flexible then it should be so constant eyeballing is required to get even the most basic cuts right. Another issue I encountered is rust specks on the 3000 pre-polish lap that reduce my usable space to a narrow band. This issue resulted in a 4 hour polish, just for the table alone. This will probably be my last stone for a while as I don't want to invest the time and my hard won material on this particular machine.

Facetron or Ultra tec.... hmm??

https://www.prospectingaustralia.com/forum/img/member-images/3340/1431830202_img_1790_640x480.jpg

Nice stone there SC - I've been meaning to post that for a while, sorry :8 I really like the "pinwheel effect" it shows

 

[Lefty]

Hartz range garnet - it has some inclusions (bubbles) but I'm glad I finished it anyway. The camera actually shows the true colour here (maybe because I took the photo in sunlight?) and you can see how the early diggers out there a century ago were fooled into thinking they had rubies.

 

[Kingsolomon]

Was wondering about the 0" on that machine . My Machine can operate the same way , yet only used that for very small tables . I like the 45" dop , take a little more time at first bit then only a minute to set ip . More control for levelling . You will find what works for you .

 

[Kingsolomon]

Put a bit of tape on your boxes to collect the excess fibres , the spongey bit. then the static from the stones dosnt collect them . Look better

 

[Lefty]

Thanks for the tip Barney - yes, a bit of fluff can ruin a photo

 

[Lefty]

Hartz range material X, cutting it in the "Lighthouse" design.

Still not certain as to what it is, picked it up out there about 5 years ago. Looks like clear quartz but has some things about it that have always made me wonder. It displays a perfect-looking cleavage plane which quartz does not have. Am sending a bit of to a gemmologist, hopefully he will solve a five year old mystery.

I suspect it might be petalite but I'll have to wait to find out.

Finished the pavillion last night. Tried to polish on #60 000 diamond - didn't do a very satisfactory job. Moved to cerium oxide and it quickly took on a nice, bright polish. One of the huge facets - lighthouse has only four big pavillion facets - polished with some difficulty, though it did eventually take on an acceptable finish. Looking through the loupes, there are minute inclusions just under the surface of that facet, like tiny needles all running the same direction. They actually appear to go right through the stone but are invisible through the other three facets. I haven't seen anything that looks quite like this in any of the quartz I've faceted so far.

The stuff looks like it would make a nice, bright gem. Will see how it turns out when I hopefully finish it today since I ain't going in to work.

 

[Varts]

very interesting yhere lefty

 

[GallicProspector]

Some kind of feldspar maybe (moostone, labradorite, all the same family)?
Softer than quartz, takes a beautiful finish on cerium.

 

[Lefty]

It finished up brilliantly!

Unfortunately, it's pretty pointless taking a photo since no matter what I do the camera just sees it as a square bit of glass. The eye sees it as brilliant silver.

Seems to be a good cut for light-coloured materials.

 

[Sodabowski]

Any occurences of kunzite in the region? This could be one...

 

[Kingsolomon]

Hartz range material X, cutting it in the "Lighthouse" design.

https://farm1.staticflickr.com/408/18446173385_4d6e06da58_c.jpg

Still not certain as to what it is, picked it up out there about 5 years ago. Looks like clear quartz but has some things about it that have always made me wonder. It displays a perfect-looking cleavage plane which quartz does not have. Am sending a bit of to a gemmologist, hopefully he will solve a five year old mystery.

I suspect it might be petalite but I'll have to wait to find out.

Finished the pavillion last night. Tried to polish on #60 000 diamond - didn't do a very satisfactory job. Moved to cerium oxide and it quickly took on a nice, bright polish. One of the huge facets - lighthouse has only four big pavillion facets - polished with some difficulty, though it did eventually take on an acceptable finish. Looking through the loupes, there are minute inclusions just under the surface of that facet, like tiny needles all running the same direction. They actually appear to go right through the stone but are invisible through the other three facets. I haven't seen anything that looks quite like this in any of the quartz I've faceted so far.

The stuff looks like it would make a nice, bright gem. Will see how it turns out when I hopefully finish it today since I ain't going in to work.

I ve been looking for that. Design . Have you got. A pic or a link for me?

 

[Lefty]

Try this link Barney.

https://www.gemsociety.org/.../online-faceting-designs-diagrams-light-house/

It isn't opening for me at present, if the link itself is broken I might be able to take a clear photo of the photocopied page and post it here this evening.

 

[Lefty]

Any occurences of kunzite in the region? This could be one...

There seems to be occurences of heaps of different things in the Hartz range area Thomas. I could easily spend months camped out there scratching aound - but I know someone who would have something to say about that

I don't know much about kunzite but I thought it was supposed to be a fairly difficult sort of stone to work with. This stuff cut without any difficulty and once I switched to cerium it polished up quickly and very nicely.

It could ultimately turn out to be just nice, clear quartz (I have to get my bum into gear and send a few bits off for testing) but I know that gem quality petalite is found at Hartz range.

Petalite and quartz have a similar appearence, fairly similar hardness (given that Moh's scale is a little simplistic), fairly similar SG, both display a conchoidal fracture, can both contain black tourmaline needles - biggest difference is that petalite has a strong cleavage plane while quartz has none. Many of these pieces have a blocky sort of appearence and there is just something about the stuff that's hard to put my finger on that leaves me wondering every time I tell myself it's probably just quartz.

Interestingly, if petalite - lithium aluminium silicate - is heated to 500c and held there it actually becomes quartz as the lithium and aluminium leave the compound.

 

[Lefty]

Barney, do you have any tips for cutting and polishing the Springsure stuff?

I thought I had the latest bit oriented away from the cleavages but when something is perfectly cleavable in three directions, I'm not sure how easy it is to avoid at least one facet coming close to a plane.

One facet was virtually bang on one - it kept pitting and flaking while polishing and through the loupes i could see it was covered in perfectly paralel striations. An adjoining facet on a similar angle was also affected, though not as bad. I eventually had to accept it wasn't going to achieve a nice smooth surface. Stone still looks nice but I couldn't bring myself to set the stuff in jewellwery until I can be sure I can polish it perfectly.