George Eliot said These gems have life in them: their colors speak, say what words fail of. It is possible to make gems really speak by carrying a message.
Gems have adorned many a story and many a leading figure but there are other uses for gems. The rich, especially those with a guilty conscience (think dictators and crime bosses) are known to keep small cases of diamonds on their person at all times, not for aesthetics but as a ready source of wealth in exile. Fancy colored diamonds, even ones that are rather ugly, serve as a highly portable, compact source of wealth: a cigarette case might hold ten or a hundred million dollars in diamonds, if they are the right type of diamonds. When you hear of the latest outrageous price per caret of a blue or red diamond, it is almost certainly on behalf of a very rich person that wants to turn a lot of money into a discreet form.
There’s much more one can do with gems though. This post deals with real-world physical properties of gems that might be of use in a story. Most of these ideas are probably better suited for a contemporary thriller or science fiction but some might be of use in fantasy.
Consider means of encoding information with gems. Many of you may already be aware that some diamonds have microscopic serial numbers inscribed on them. These can be used to identify them after a theft or to mark their origin (to avoid “blood diamonds” for instance.) Nothing says the information has to be a simple serial number though: one could inscribe any short message on a diamond or other gem stone, from a security key to an incriminating message. Or perhaps someone has used the serial number on their diamond as their security key?
But physically inscribing a gemstone is just one of many ways to store information with gems. One could take advantage of colored stones or even the names of stone to encode a message in a tennis bracelet. For instance, the color of a gem could be assigned an ordinal number from the colors of the rainbow (old Roy G. Biv: Red, Orange, Yellow, Green, Blue, Indigo, Violet). Seven colors for seven numbers could serve to encode a combination key or any number in base 7 (an odd base to use but converted easily enough to more common base 10.) Other color encodings can exist. Or the encoding might rely on the name of the gems: sapphire for S, Ruby for R, etc. This could result in a rather garish (and obvious) bracelet though. Thankfully, there are more subtle encodings available.
More subtly, one can use facets to encode information. It would be tricky and require a good stonecutter (thus creating a lead for a sleuth) but one can modify standard cuts. A standard round brilliant cut diamond has 58 facets but a good stone cutter can omit or add facets. This could be in a fairly obvious manner, such as a missing facet so that anyone with a loop might notice the omission or it could be done as a variation of the brilliant cut that might require more careful analysis (57 properly spaced facets rather than 58 might take careful work to notice). You could alter a specific facet for a binary encoding (standard brilliant, altered brilliant) but with 58 facets to play with you could encode a lot more information into a single stone depending on how much you wanted to affect the look of the cut stone. However, alter the standard cut too much and even a novice might notice it.
Beyond names, colors and shape of the stone there are still more properties to work with. Pleiochroism is an optical property that changes the color of a stone depending on the axis through which it is viewed. Most gemstones exhibit this property but you may be unaware of it as any good stonecutter knows about this and takes advantage of it. In many gemstones, the color change is more a matter of intensity: some sapphires for instance are more intensely colored along the axis of gem growth and weakly colored perpendicular to that axis. Therefore these stones are cut so the face is along the axis to deepened the blue (or other color for fancy sapphires). But sometimes a stone can be too dark and the color could be lightened by cutting against the axis.
However, there are some stones that actually display a different color depending on the angle of viewing. Iolite (water sapphire) is a well-known stone with strong pleochroism. It can show blue or violet depending on the angle. It’s also a pretty cheap stone if you want to go to eBay and buy one as an example.
With simple two-axis pleochroism, you could encode a message on a strand of Iolite beads, with some beads cut on the blue axis and others cut on against the blue axis. Then you would have alternating blue and violet which could be a binary encoding. Of course, this isn’t terribly interesting since you could do the exact same thing mixing sapphires and amethyst (or purple sapphire) beads. But there is also trichroism: gemstones that show three different colors depending on how you view them.
Tanzanite is known for its beautiful violet-blue color but one stone can show blue, violet or red depending on the axis. One could imagine a tennis bracelet of carefully selected tanzanites that straight on shows violet but when viewed from the side show blue or red depending on how the stone is placed in the setting, resulting in another binary encoding. If you wanted a really tricky code, you could actually use the blue/red dichroism to encode a rotation (probably using some quanta related to the number of facets in the crown) instead of just a binary value. This would make it very hard for someone not in the know to realize there is an encoding on the bracelet. Quite diabolical.
Another gem property that can carry a hidden message is fluorescence. In some gemstones, there is a wide variation in whether a given specimen fluoresces or not. Diamonds are one such stone where it is used to prove the authenticity of famous jewelry pieces. Some diamonds fluoresce blue or yellow, some show little or no fluorescence, even if in normal light they all might look identical. Back to our handy tennis bracelet: by selecting fluorescent and non-fluorescent stones, one could create a binary (or higher base if one makes use of a range of fluorescent colors) message, one that is only visible with a UV light.
These are all different ways I can imagine that a spy or unwitting socialite was carrying a message on his or her person. Maybe daddy doesn’t give a damn about his daughter, he just wants that tennis bracelet off her wrist because it is the key to his Swiss safe deposit box!
Most of these techniques require modern scientific methods to use or at least an understanding of physical properties that might be out-of-place in a fantasy novel but they might make for a nice twist in a modern mystery or a science fiction novel.
Gems are one of my minor hobbies and I will be following up this post with some additional ones on specific gems. If you have one you are particularly interested in, let me know in the comments and I’ll see if I can get to that one first. Otherwise, I will probably start with garnet and tourmaline, both secondary stones with a wide range of colors and properties.
- Top 10 Record Breaking Gemstones (toptenz.net)
- Navigating New Territory with Iolite (loriaandrus.com)
- Special Gemstone Effects (pippatreevintage.wordpress.com)