Sneaky Gems.
- Thread starter SneakyCuttlefish
- Start date
Help Support Prospecting Australia:
:Y: :Y: :Y:
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
So I have been working on a new design for another Swiss Smokey. I haven't been able to find a square design that looks any good or performs the way I want so I have trialled 18 different customised crown and pavilion combinations and finally settled on this combination. Its called Geordi's Visor (one for the trekies). Performs really well in quartz through to Beryl. Any higher RI's and the crown is flattened out too much. The GemRay graph shows good flat to slowly peaking performance at 60% which is better yield than an SRB. Not as bright as my Mitsubishi Trillion though. That yielded solid performance at 80% across all light conditions. (though, trillions are typically brighter than most cuts) . I'll be testing it out in a topaz this weekend.
.
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
I have also been working on a round brilliant for sapphire with the aim of achieving extremely high brilliance with a very striking face up image. This one is called a Chernobyl Brilliant...... because its so radiant.... 
(too soon?)
Anyway, it achieves a 20 percent increase in brilliance over an SRB calibrated for corundum, with a slight drop in brightness at 0 degrees (SRB follows the same pattern). The crown to pavilion ratio is spot on and it provides a striking face up image as well. I'll be attempting to cut it into a topaz soon. When calibrated for topaz the cut is a very steady 60% without the drop in brightness at 0 degrees that the SRB produces. That means this cut in lower RI's is actually the perfect cut as it maintains the same brightness regardless of the angle the stone is viewed from. There need only be a 2 degree drop in crown mains and a 2 degree increase in pavilion mains to achieve calibration for topaz as well which is quite an improvement over other designs I have created which require wild angle changes to achieve optimisation. I think this one is going to be a real winner but I need to get some good sized sapphire to be absolutely sure its suited. Anyone care to donate for science?
(too soon?)Anyway, it achieves a 20 percent increase in brilliance over an SRB calibrated for corundum, with a slight drop in brightness at 0 degrees (SRB follows the same pattern). The crown to pavilion ratio is spot on and it provides a striking face up image as well. I'll be attempting to cut it into a topaz soon. When calibrated for topaz the cut is a very steady 60% without the drop in brightness at 0 degrees that the SRB produces. That means this cut in lower RI's is actually the perfect cut as it maintains the same brightness regardless of the angle the stone is viewed from. There need only be a 2 degree drop in crown mains and a 2 degree increase in pavilion mains to achieve calibration for topaz as well which is quite an improvement over other designs I have created which require wild angle changes to achieve optimisation. I think this one is going to be a real winner but I need to get some good sized sapphire to be absolutely sure its suited. Anyone care to donate for science?
Some interesting designs, love the look of your Chernobyl Brilliant.
If no one will donate to your sapphire for science cause, i have a bit of synthetic with some nice colour you would be welcome to
If no one will donate to your sapphire for science cause, i have a bit of synthetic with some nice colour you would be welcome to
- Joined
- May 1, 2014
- Messages
- 1,958
- Reaction score
- 2,530
Looks great SC. I would definitely test them on material that isn't valuable or special first though.
As I said in the other thread, I don't have either Gemcad or Gemray but will definitely end up getting them as most people recommend them highly. One thing I have noted though is that some people have said they've found that computer-generated raytracing can sometimes be a little misleading. A commentor on another forum remarked that he has cut designs that the modelling suggested would be pretty dull but turned out great in real life and also cut ones that modelling suggested would be outstanding but actually turned out a bit ordinary.
While I don't posses the software I can attest to this, having cut a number of designs that were available on the web which the author stated were not yet tested - a couple were great but one or two simply failed to live up to the author's description of how they would turn out, despite me doing everything exactly to the letter, selecting the correct RI materials etc.
Perhaps my expectations were too high. I do tend to think though that while the software is very good, we probably aren't yet at the stage where a computer sees things exactly the way the human eye perceives them.
As I said in the other thread, I don't have either Gemcad or Gemray but will definitely end up getting them as most people recommend them highly. One thing I have noted though is that some people have said they've found that computer-generated raytracing can sometimes be a little misleading. A commentor on another forum remarked that he has cut designs that the modelling suggested would be pretty dull but turned out great in real life and also cut ones that modelling suggested would be outstanding but actually turned out a bit ordinary.
While I don't posses the software I can attest to this, having cut a number of designs that were available on the web which the author stated were not yet tested - a couple were great but one or two simply failed to live up to the author's description of how they would turn out, despite me doing everything exactly to the letter, selecting the correct RI materials etc.
Perhaps my expectations were too high. I do tend to think though that while the software is very good, we probably aren't yet at the stage where a computer sees things exactly the way the human eye perceives them.
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
Thanks shivan. I will take you up on that offer. I'll send you a PM.
I agree lefty. I use Gemray as a guide to adjust angles to suit different RI's and to check estimated internal patterns but this program is not the best for the latter. It can show an image of what the stone should look like but its not always the case. Interpreting the data is also requires a bit of understanding and experimentation.
What some people don't realise is that the dark patches in a GemRay face-up image is actually the viewer being reflected inside the stone not leakage. This seriously impacts on the performance of a piece either to enhance the stones brilliance or diminish it. So for example, the chernobyl brilliant above has eight triangle points and an octagon inside that will reflect the viewer. (octagon is not actually in the design, it is an illusion created by interactions between the pavilion mains and the table shape)
These areas still count as "brightness" to the program because light will still travel into the stone, hit the facet and reflect straight back out the crown. These facets are at the right angle to reflect an image rather than appear as a pane of light. Even though mathematically speaking, image reflection counts as brightness. Too much will actually rob the stone of its brilliance. (big difference between brilliance and brightness in my opinion)
The image below is of one of my earlier designs (sundown barion). This design performs very well on GemRay. It has a crazy internal image and this image translates exceptionally well into a cut stone BUT, there is too much image reflection and the stone in real life is quite dull to look at.
On the other side of the coin, this is a GemRay image of my Mitsubishi trillion (cut smokey in the thread above). It performs exceptionally well in GemRay and translates exactly as predicted into the real world (minus the minuscule inaccuracies that a human can't account for but a computer can)
The difference in real world performance compared to their perspective GemRay performance in my opinion, can be put down to 2 simple factors:
Trillion centre has no or limited image reflection in the centre which is the part of the stone that most catches the eye = excellent real world performance
The sundown has a dense accumulation of image reflective facets close to the centre. = poor real world performance
I have found that a good design requires a balance of light reflection and image reflection to create an internal image that doesn't impede the brilliance of a piece. Anyway, that's my understanding based on my experiments. If someone reading this has a different opinion I would love to hear it. The programs don't exactly come with a course in gemstone design so any idea is an idea worth exploring.
I agree lefty. I use Gemray as a guide to adjust angles to suit different RI's and to check estimated internal patterns but this program is not the best for the latter. It can show an image of what the stone should look like but its not always the case. Interpreting the data is also requires a bit of understanding and experimentation.
What some people don't realise is that the dark patches in a GemRay face-up image is actually the viewer being reflected inside the stone not leakage. This seriously impacts on the performance of a piece either to enhance the stones brilliance or diminish it. So for example, the chernobyl brilliant above has eight triangle points and an octagon inside that will reflect the viewer. (octagon is not actually in the design, it is an illusion created by interactions between the pavilion mains and the table shape)
These areas still count as "brightness" to the program because light will still travel into the stone, hit the facet and reflect straight back out the crown. These facets are at the right angle to reflect an image rather than appear as a pane of light. Even though mathematically speaking, image reflection counts as brightness. Too much will actually rob the stone of its brilliance. (big difference between brilliance and brightness in my opinion)
The image below is of one of my earlier designs (sundown barion). This design performs very well on GemRay. It has a crazy internal image and this image translates exceptionally well into a cut stone BUT, there is too much image reflection and the stone in real life is quite dull to look at.
On the other side of the coin, this is a GemRay image of my Mitsubishi trillion (cut smokey in the thread above). It performs exceptionally well in GemRay and translates exactly as predicted into the real world (minus the minuscule inaccuracies that a human can't account for but a computer can)
The difference in real world performance compared to their perspective GemRay performance in my opinion, can be put down to 2 simple factors:
Trillion centre has no or limited image reflection in the centre which is the part of the stone that most catches the eye = excellent real world performance
The sundown has a dense accumulation of image reflective facets close to the centre. = poor real world performance
I have found that a good design requires a balance of light reflection and image reflection to create an internal image that doesn't impede the brilliance of a piece. Anyway, that's my understanding based on my experiments. If someone reading this has a different opinion I would love to hear it. The programs don't exactly come with a course in gemstone design so any idea is an idea worth exploring.
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
This is another I have finally finished. Its called a Grenadier Brilliant (looks like an explosion in the middle of the stone).
This one is ONLY for corundum and above. It performs well in diamond with a slight crown angle adjustment but I doubt I'll be cutting any of them anytime soon. In corundum it performs much like the "topaz adjusted Chernobyl brilliant." Very uniform performance at 70%. Almost the same brightness across all degrees of tilt. Only problem is there are an extra 32 facets to do.
Would look fantastic in a nice Ruby
...... Science is a good cause..... donate to science today
This one is ONLY for corundum and above. It performs well in diamond with a slight crown angle adjustment but I doubt I'll be cutting any of them anytime soon. In corundum it performs much like the "topaz adjusted Chernobyl brilliant." Very uniform performance at 70%. Almost the same brightness across all degrees of tilt. Only problem is there are an extra 32 facets to do.
Would look fantastic in a nice Ruby
...... Science is a good cause..... donate to science today
Lovely work there. ]
Beautiful Sneaky.
Mackka
Mackka
Send me your details and i may be able to send out a bit of red and blue to test em out on.
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
So this is the Chernobyl Brilliant 8mm stone. 5.5 carat. VVS1 Clarity. Very very pale green/blue topaz from Coolgara Station.
Several different light conditions. I couldn't quite capture the internal octagon but the points show up well. This cut is very fun to do. The meet points are simple and its quite quick. However, some of the crown facets and one pavilion sequence had to be cut in with a 3000# BATT pre-polish as they are extremely easy to over cut.
Please excuse the dust and oils. It is incredibly hard to clean stones for photo's on a mirror. Even the tiniest bit of junk on the mirror or the stone just beams in the light and is reflected many times over.
Several different light conditions. I couldn't quite capture the internal octagon but the points show up well. This cut is very fun to do. The meet points are simple and its quite quick. However, some of the crown facets and one pavilion sequence had to be cut in with a 3000# BATT pre-polish as they are extremely easy to over cut.
Please excuse the dust and oils. It is incredibly hard to clean stones for photo's on a mirror. Even the tiniest bit of junk on the mirror or the stone just beams in the light and is reflected many times over.
Hey Sneaky I wa just wondering what you do with your creations, sell them ,store them or show them?
Just curious. Love ya work mate.
Mackka
Just curious. Love ya work mate.
Mackka
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
Speaking of photography issues, my brother in-law is a pro photographer and he recently acquired a ridiculously powerful macro lens. We did a few photo shoots of some of my earlier gems and had a play around with lighting. Loads of fun and they turned out great. I couldn't believe how powerful the lens was. I would love to have a good set up like his but 6k for the camera and 2k for the lens is a bit off putting. I'd rather buy a big chunk of tanzanite for that kind of coin.
(the lens is so powerful it picked up a scratch on this one that can't be seen with a 60x loupe)
Nice mix of topaz, zircon, demantoid garnets, tsavorite and peridot. Once again the dreaded oils and dust show up like a beacon. Does anyone know how to get a perfectly clean stone? Is there a better cleaning agent to use other than alcohol?
(the lens is so powerful it picked up a scratch on this one that can't be seen with a 60x loupe)
Nice mix of topaz, zircon, demantoid garnets, tsavorite and peridot. Once again the dreaded oils and dust show up like a beacon. Does anyone know how to get a perfectly clean stone? Is there a better cleaning agent to use other than alcohol?
- Joined
- Jun 24, 2014
- Messages
- 316
- Reaction score
- 837
Thanks mackka
At the moment I am stock piling but I hope to have enough different stones to sell soon.
At the moment I am stock piling but I hope to have enough different stones to sell soon.
Digginholes
Greg
Wow sneaky those stones look amazing, great job!!
very very NOICE group, especially the top middle :Y: :Y:
Some amazing pics there Sneaky, doing really well mate.
