How to cut Labradorite
What was a frustrating and long journey, in the end has been a rewarding and ongoing quest. How to cut Labradorite properly seems to still be a bit of a mystery according to what all we have read in our own research (at the beginning of our journey). Most of what seems to be available as far as "how to's" is aimed at getting your Labradorite to have "a flash". We can show you that, but hopefully aim to help you learn how to cut Labradorite so you have full flash from all angles possible to decrease the limitations of setting the piece according to the flash. The flash should not dictate how you work around the stone, but rather you should dictate how the stone will flash to accommodate YOUR work.
This how to is aimed at rough or bulk Labradorite. If you have a 1/4" slab yielding little to no flash, unfortunately you may be stuck with what you have. If you have a thick slab, you may be able to taper the angle in multiple steps with the following methods. Some people and suppliers do not know how to slab Labradorite to yield the best flash, for that reason, buying rough and learning how to maximise flash is worth the effort. In the start we lost a lot of potentially good flash by settling for what was considered "a flash". Because we were just playing as a hobby, we did not know how to cut Labradorite or how to slab it properly, mostly because our sources were scarce and expensive.
After our first large shipment, I took a 1kg piece and threw caution to the wind, not caring what I wasted with the hope it would start to make more sense. I am glad we sacrificed that piece because I learned a lot.
Firstly, because of the formation, Labradorite does not always have a consistent "flash" face/plain. The larger the piece, the more inconsistent the flash plains can be. What I mean is, do not just cut it like a loaf of bread based on your first flash find. If you have found a face with full flash on a large piece of rough, do not assume it can be slabbed or cut parallel to that face right through the entire piece. Chances are you will run into what will appear to be a dead spot. Now, this may be the case, but it is also possible that you have exhausted that particular angle. Stop proceeding with that cut and re evaluate your material. I have attempted to sketch a diagram that can be found later in this tutorial to better explain our "investigation techniques" and how to cut Labradorite that exhibits multiple flash planes.
Now. . . if at any time through this tutorial, you find yourself saying "Thats too much work!" please feel free to skip right to our slabs, preforms or cab section for already calculated flash :)
How to cut Labradorite:
I like to break this down to 4 basic steps. "Identify", "investigate", "square" and then "cut".
Step one: Identify.
The above piece is a medium piece of labradorite rough, it is probably common knowledge, but just in case, make sure you get your piece wet. Water is your best friend when searching for flash. Keep a spray bottle handy and use without reserve. This is a good example of a piece with various plains of flash. I normally identify the most exposed or protruded plain to start the cutting process. This makes it much easier to make multiple slabs from various plains in the same stone, allowing you to slowly work around conflicted plains and reduce the amount of waste. The middle pic shows a nice color pattern and decent flash. This particular area is located on the "heel" of the rough, making it an ideal location to start with. The rest of this picture tutorial will focus on that plain targeted in the middle pic above.
Step two: investigate.
When we investigate, we are evaluating the faces angle and the maximum flash exposure. The first thing I do if the targeted plain is a little rough or hidden, is to give it a quick run on my flat lap. I will normally just go with the natural angle of the face. This simply allows you to observe the flash a bit more clearly. The above pic shows the target area after the flat lap and after a water spray. What the 3 pics represent is how the flash is observed while the Labradorite is rotated. Do the best you can in keeping the face parallel to your vision. You will notice that the above pics illustrate a poorly oriented flash, well. . . at least in our opinion. So from here we move to what I call investigative cuts.
If you look close, you will notice a few new faces. These are minor plain adjustments I have made on the flat lap machine to search for the best face angle. Over time you should be able to reduce the investigative cuts to a minimum, but in the beginning mine looked like a bad example of an attempted princess cut pavilion, so don't be worried. I have chosen to make two new angles. What needs to be done now, is to repeat the rotation process shown in the previous pics. Do this on all your new angles until you have found yourself an acceptable central flash. What this is attempting to achieve is to eliminate a stone that only looks impressive from a right sided observation, or left, above etc. . . When you have made your choice, (Mine being the bottom right cut) proceed to cut that angle through the entire face.
Repeat the visual rotation and pivoting method again. Notice the difference? If by chance you are not pleased with the result, repeat the investigative cut process. If you are happy with the flash, move onto squaring up your piece.
Step three: Square
This step is just a quick and dirty method to ensure you get a decent foundation on your Labradorite for running through your saw. You can skip this step if you use a plaster cast method, have a sliding vice on your saw, don't want to potentially waste material or have immaculate eyeball accuracy. The objective here is to make a 90 degree plain off your newly found face to use as a foundation for the table of your saw. This just helps run the rough through the saw leaving the only concern being to keep the face parallel to the saw blade itself. The above picture represents the perfect angle the rough should be while cutting the foundation face. All you need to do is get any area, strip, side etc. . . 90 degrees to the flash face.
This is just an example picture showing an area that can be removed to achieve this. Ideally you should rotate your square around the Labradorite and find the area that will require the least amount of material to be removed to achieve this. In the above pic, the material over lapping the square can be removed to get the result.
This is the area I chose. Your result will look something like the above pic.
Lastly the result. The rough is sitting sturdy on the foundation cut, and my face is a perfect 90 degrees. This simply makes running the Labradorite across the table easier and eliminates the rough from wanting to roll or pivot. I will admit, I typically only use this method if I find a very desirable flash making what little waste the foundation cut causes, little concern. Now lets cut a piece to see the yield.
Step 4: Cut
Here is the end result. A successful full flash no matter the stones orientation. After all of that, I was able to get approximately 3, 1/4" thick pieces to cab with a great pattern and strong flash before that particular area was exhausted. At which point I repeated the process' for all the other areas with great potential.
How to cut labradorite rough with multiple flash plains.
The following rough sketch shows the steps I use when cutting material with various areas exhibiting flash. This will help maximise the amount of quality material you can yield from your Labradorite rough while wasting less material.
Lets pretend your piece of rough has come in the shape of a convenient cube (its convenient for sketching too). The blue in fig: 1 represents the ideal flash and is what we are looking for when investigating the Labradorite rough. By using the earlier methods in identifying central flash, cut your first plain ending roughly what fig:1 represents. From here you can safely cut your Labradorite slab. The green lines represent the blades path.
Fig: 2 is the result from the first slab being removed. The lighter blue represents a less than ideal flash starting to emerge from the right side. Depending on the quality and size of the new flash plain compared to the old, you may decide to continue slabbing and just write off the poor flashing area as scrap, or, you can proceed to make investigative cuts to evaluate the quality and depth of the new plain.
In fig: 3, you see 3 areas bordered by a green outline. These are examples of the areas you investigate to try and find the central flash face of the newly emerged plain. You can cut or simply use your flat lap machine to achieve this. Trimming a corner or two, and slightly refacing the centre edge, which are fairly non invasive areas to look at.
Now in fig: 4 you will see the 3 investigative cuts that we have made. Again, by using the rotation method to observe the maximum flash capability of the faces you can determine what new cut if any is the ideal one. The upper right corner of fig: 4 exhibits the ideal blue we are looking for and will be the new plain we combine in the next few cuts.
Fig: 5 represents the new cutting paths we will use to yield both flash faces. We will obviously cut the upper right slab first, then the same path as the cut in fig: 1.
The result from those two cuts is shown in fig: 6. These examples may be a bit extreme, but are just that, examples. What you will see in fig: 6 is another new plain in the bottom right, a fourth in the left middle and the previous new plain has resided a bit. The dark plain has come in an awkward location and do to its size and placement we will ignore it and just work around that area after we slab it.
In fig: 7 we see the same cutting and investigative steps as earlier. Lets assume we found the bottom right face and it was worth cutting a slab from. So we now make the slab cuts.
Fig: 8: is the results from the 3 cuts. We have good consistent corner plains but now the dark plain in the left has grown and is overpowering our original face.
So again, we investigate in fig: 9 and identify the the new left side central flash plain angle to be cut, and also continue with the upper and lower right side slabs.
We hope this has shed some light on the topic. If you have any questions, comments or even additional advice to add, we would love to hear from you at firstname.lastname@example.org