Published Summer 2001

Contents: Mine all Mine DIY stone cutters, concave faceting, Zeolites series, quiz, news and events.

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Concave Faceting

In the summer of 2000, I decided to try concave faceting as a variation of the usual method that relies on flat surfaces.
As I had only seen pictures of concave stones and the machines on which they are cut, it seemed wise to start with a few preliminary experiments. There can be far more variation with curved facets than with the flat variety. A spherical lap, for example, if held in one position while cutting, will cut a 'dimple' shaped facet of its own diameter. While there are possibilities of decorating a stone with such dimples, this shape does not lend itself to producing meet points around the stone. A cylindrical lap is much better in this regard and can be made in different diameters for variation. As a beginner in this field, I have not yet explored other lap shapes.
My first try at concave faceting consisted of cutting DOMET a dimple in the table of an otherwise normal round brilliant. Although dissatisfaction with this stone convinced me that I should move on to cylindrical laps, other people who have seen it seem quite impressed - I suppose that it depends on what one expects. I cut and polished the dimple more or less freehand but, before attempting to cut cylindrical facets, I made an attachment enabling my faceting head to be fitted to my Myford lathe. Matters would be fairly simple if the stone could be held stationary above the rotating lap. This approach would result in transferring the surface variations of the lap to the stone, however, and produce a poor finish. Moving the carriage of the lathe, on which the faceting bead was fixed, back and forth solved this problem but became somewhat tiresome. Despite the fact that the finished stone did not have a high degree of polish, the overall effect was good enough to make me want to carry on.
I usually sit in comfort while faceting and so having to stand up and rock the lathe carriage while cutting a stone was not very appealing. The price of a commercial machine turned me away from that option, leaving little alternative to building my own. Although the cost of parts for my concave faceting attachment was not high, I did invest a fair amount of time in the project without knowing whether I would have a useful accessory when it was completed. The main difference between my concave attachment and the lathe set-up is that the former has a reciprocating spindle/lap, removing the need to move the faceting head back and forth. The whole assembly may be rotated so that facets can be angled with respect to the axis of the stone.
It has taken me some time to work out lap combinations that will give a satisfactory finish on various materials when cutting flat facets. These same combinations would obviously also work when I moved onto concave faceting, wouldn't they? Well, not quite. It has taken quite a lot of experimenting to work out a combination of laps! techniques that produce a good finish.
Until starting to cut stones with concave facets, my faceting consisted mainly of following designs printed out from a computer program called 'GemCad'. Although there is considerable skill required to produce high quality stones by this method, there is also a certain amount of predictability. When moving on to concave faceting, I could not rely on computer assistance because 'GemCad' cannot handle curved surfaces.
Cutting a concave version of a round brilliant presented little difficulty but I was in for a shock when I began cutting angled (to the axis of the stone) facets. The advantage of such facets is that they produce a swirling optical effect that I have not seen in flat faceted stones. Once one becomes accustomed to the controls of a faceting machine, it is relatively straightforward (in principle, anyway) to make adjustments that will correctly position a flat facet. The lack of a preplanned design and greater unpredictability of angled, curved facets makes the situation much more complicated. I am not especially good at working with concepts in 3D and so I was forced into a cut first, cry afterwards approach. Positioning the facets and making them the required length was really difficult. Cutting past a meet point or removing material from the wrong position means starting again, of course.
Considerable practice has helped me come to terms with this type of faceting, however, and I can now place facets more accurately without over cutting (most of the time). I feel sure that passing on the technique to someone else would be much easier than learning myself by trial and error. I have cut stones with concave surfaces on every facet except the table and others with various proportions of flat and concave facets. By using concave girclJe facets, shapes that are unobtainable with the flat variety can be cut. On the downside, the spiky nature of concave girdle facets, especially if there are only a few of them, makes the stones more prone to damage during cutting and setting. Cutting tiny flat facets on the spikes will reduce this problem.
I have kept notes about the angles, index numbers and degree of rotation to the axis of the stone since I began concave faceting. With simple designs, this information is sufficient to enable me to cut a similar stone. When I tried to replicate a complex design, however, I produced a very different stone - good for creativity, bad for consistency. I think that more detailed notes with appropriate sketches would be necessary if accurate reproduction were a requirement - my web site now has some pictures to go with the instructions:
Although I have not yet produced many concave faceted stones, I am really pleased with the machine that I built. Every new stone offers the chance to experiment, and flat faceting seems much less complicated when I return to it.
Chris Algar


Humans have been attracted by the beauty and magic of gemstones for thousands of years. Evidence of people using and wearing gemstone jewellery goes back to the Stone Age.
Malachite, lapis and carnelian were the favourite gems of the Egyptians, the Incas loved gold and emeralds, turquoise and coral are sacred to Native American Indians and Tibetans and have been used a lot in their jewellery as well as for rituals and healing. The favourite gemstone for the Chinese is jade and the Celts used to love flint and smokey quartz.
In many excavations, archeologists find jewellery and other items made from precious and semi-precious gemstones in the graves of the rich, famous and powerful people of the past. Crystals and gemstones have been worn throughout the ages to display power and wealth, but the knowledge about the healing properties of those stones can be traced' back as far as Atlantis and Lernuria.
Today we can witness a re-awakening of mankind towards the healing and transformational qualities of gemstones.
The easiestway to access these qualities is by wearing them as jewellery. Wearing a crystal pendant can energise, heal, balance and protect your energy field all day long. The best position to wear a pendant for good health is in the centre of the body above the thymus gland Gust below the sternum) here it activates the self-healing powers and boosts the immune system.
Stones to improve expression and speech (lapis lazuli, turquoise etc.) are best worn as close to the throat chakra as possible. If you are working on emotional problems or you want to boost your heart chakra, the appropriate pendant should be worn above the heart.
Earrings work best for boosting the top three charkas which are in charge of spiritual wellbeing, vision and expression and promote the interaction of these three energy points. The colours for these charkas are purple, indigo and blue and earrings made from gemstones in those colours have the best impact. This would be, for example, amethyst, tanzanite, sapphire, blue topaz, lapis, turquoise and others. Gemstone rings are traditionally worn as symbols of eternity and union but work well for healing as the energies are carried by the meridians to specific parts of the body.
Arm and wrist bands are used to heal an influence in the half of the body they are worn on. They work specificallywell for pain relief such as rheumatism and arthritis.
People love their jewellery. This relationship is often very intense, deep and intimate. It is most important to find the right piece of jewellery to match the frequency of your energy field and here are a few guidelines of what you have to look out for when choosing the right piece for you:-
The gemstone has to be of good quality and without damage or cracks. If it is a crystal, you should check that the termination is perfect and undamaged.
.:. The setting should be in silver or gold or the two metals combined. Gold promotes a male (yang) energy and symbolises the Sun while silver tunes into the female (yin) energy and relates to the Moon.
.:. The setting should not be flimsyor fragile and should alwaysbe open towards the back so the stone touches the skin when worn. This is also the case for rings.
.:. If there is more than one stone in one piece of jewellery, make sure that the different gems complement each other in their energies and look and feel harmonious.
.:. You should find out exactly what stones there are and the locations where they were found and if possible find out who made the piece of jewellery and whether this person was aware of the healing powers of gemstones.
Whether it is a unique piece or a reproduction, it is most important to find out as much as possible about the piece of jewellery you're choosing as it helps you to connect and bond with it.

Different Stones for Different Purposes

Black stones generally absorb negative energies and are good for protection. Black tourmaline works very well in absorbing negative energies from computers and electrical appliances.A piece of black tourmaline worn as a pendant will protect the wearer while working on the computer. Black tourmaline is also found growing inside a quartz crystal where the quartz magnifies the protective qualities of the tourmaline and so would work best for this purpose. Other black stones are black obsidian, onyx and jet. While black stones absorb negative energies like a black hole, the blue moonstone and labradorite helps to build up a protective energy field around your body and so keeps unwanted energies out. Quartz crystal does a similar thing by boosting your own energy field and so strengthening it. Amethyst is often used as psychic protection and protection during meditation. Always remember that protective stones need to be cleansed as often as possible.

Rose Quartz is a stone that is very often used for calming and relaxing as well as for emotional healing and balancing. Again, it works best worn above the heart for that's where most of our emotions are processed. Green stones in general, but especially green tourmaline and moss agate are very good against stress and have a very calming effect.They can be worn or held in the hand as holding or healing stones. Amazonite goes deeper and works on the central nervous system where it helps in more chronic cases of stressand anxiety.Amethyst is very calming for the mind as stress is often created as a result of an overcharge in brain activity.Wearing a piece of amethyst will help you to keep calm and in control during stressful situations at work.

Malachite and crysocolla are very good stones to draw out aches and pains.They work very well for conditions such as arthritis, aching joints and muscles. This is mainly due to their high' copper content and we have a' very good success rate in wearing them as bracelets or holding them as large tumbled stones and handling them as often as possible.
Sugalite works very well in pain relief especially when it grows together with the black mineral called manganese. This combination of stones works wonders against head and backaches.
Amber has been traditionally used for the healing of open wounds and is also very popular for easing the pain of teething children. In this case a beaded amber necklace would be most effective.
We hope that with these guidelines will make it easier for you to choose your next piece of jewellery and will help you to enjoy crystals and gemstones on a new level.
by Lui Krieg

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