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