| Lighting | | | | Ruby was one of the first gems to be treated, |
| | | | with reports detailing the heat treatment in |
| Proper lighting is crucial with any colored | | | | Sri Lanka dating back over 1000 years. But |
| stone, but it is particularly important with | | | | today's treatments are far more sophisticated |
| ruby. The culprit is the fluorescent tubes so | | | | than the primitive heatings of years gone by. |
| much a part of the modern office. | | | | |
| | | | Today, ruby heat treatments run the gamut. |
| Most fluorescent tubes are so red-deficient | | | | The simplest is heating to knock out the blue |
| that what they do to the color of a ruby | | | | component that makes a stone purplish. Such |
| should be outlawed. The reason is not hard to | | | | heating can be done at lower temperatures |
| fathom. Ruby requires a light source with at | | | | (say 700-1200 °C) and is often |
| least some red in it, and fluorescent tubes | | | | undetectable. |
| ain't got none. Thus to bring out the | | | | |
| inherent beauty in your stones, use halogen | | | | Another type involves heating to higher |
| or incandescent bulbs, or natural skylight. | | | | temperatures (1200-1800 °C) to remove |
| | | | rutile silk, and this is generally |
| When using skylight (not direct sunlight) to | | | | detectable. |
| view gems, keep in mind that red stones will | | | | |
| appear best around noon, while blue stones | | | | But the type of heating that is most |
| look their finest just after sunup and just | | | | controversial is that applied to Mang Hsu |
| before dusk. So the rule is, if buying with | | | | rubies. This involves heating (1200-1800 |
| natural light (skylight), don't buy rubies | | | | °C) in the presence of a flux. The flux |
| (or red spinels) in the middle of the day. | | | | produces healing of surface-reaching |
| | | | fractures and openings. Thus a highly |
| Background checks | | | | fractured stone can be healed and the |
| | | | fractures dissipated. |
| A word should also be said about the viewing | | | | |
| background. At mining areas in Burma and | | | | A further treatment occasionally seen is |
| elsewhere, rubies will often be sold on brass | | | | oiling/staining. Gentle heating in alcohol |
| plates, yellow table tops or in stone papers | | | | (be careful!) can generally remove oils |
| with yellow liners (flutes). This makes the | | | | stains. |
| purplish red color more reddish. Place your | | | | |
| stones on a white background for accurate | | | | One of the true tragedies of gemstone |
| color assessment. | | | | enhancements is that they raise expectations |
| | | | among the gem-buying public to unreasonable |
| Parcels | | | | levels. Once a customer has seen the shocking |
| | | | reds produced by human tampering, it becomes |
| Buying parcels is a specialized area beyond | | | | far more difficult to accept the more |
| the scope of this article, but I do want to | | | | ordinary hues of nature. No where is this |
| mention that parcels often look great with | | | | more true than with Maing Hsu ruby. |
| all the gems piled together. This is because | | | | |
| they draw color from one another, with each | | | | I will not go into enhancement ethics. But it |
| gem adding color to the whole. For an | | | | is essential that both buyers and sellers are |
| accurate assessment of color, spread the | | | | aware of the presence of any treatment, for |
| parcel out such that individual gems do not | | | | they can have an important impact on value. |
| influence the color of those nearby. | | | | It is my personal opinion that, when spending |
| | | | a significant sum of money on a ruby, one |
| Treatments | | | | should avoid treated stones of any kind. |
| | | | |