Guzheng Alive is against using turtle shells for nails, however, as it is the single most iconic nail material it has inspired the creation of many nails that look similar. Here are ways to identify what material your nails are made of.
1a: Turtle Shell
This is a sample of turtle shell nails. Notice the way the colors blend together and transition from one color to another. The boundaries between colors are rough. Colors bleed in and through each other.
Click on the image to zoom in.
1b: Imitation - Droplets
These are man made. The patterning is created by mixing two colors of plastic or resin. Notice how you can identify discrete droplets with clean, smooth borders. This is not how turtle shell grows. Nails with this pattern are man made. Remember, from GZA’s perspective that is a good thing!
You can see something similar if you conduct an experiment at home: place a droplet of pen ink into a shallow pan of water and watch how the ink behaves. You’ll see moments like this.
1c: Imitation - Diffused
These are man made, created by mixing two colors of plastic or resin. If the previous set of nails were the ‘before’ these are the ‘after’. The plastic sat so long in a liquid state that the colors mixed, turning almost the entire nail brown. The left thumb nail (bottom left) offers great contrast. It was hardened earlier, like the set above, and does not show that general, light brown color.
2: Microcracks or Haze
Placing nails under direct light reveals clues to their makeup. Man made nails can reveal microcracks or a haze, almost as if they are covered in dust.
Microcracks are boundaries that formed as the material hardened. These are not always visible in man made nails, but if hazing is visible then those nails are guaranteed to be man-made.
Get up close and personal with a set of man-made nails and you may see layering.
Quite literally, layering is when one layer of liquid was set, cooled slightly, and then a second layer was poured on top. The difference in temperature and/or allowing one layer to partially harden prevents the layers from mixing. This can be repeated to add more layers.
Look close at a set of nails and you may see how the colors of the nails are locked in layers, essentially spreading along a plane. Turtle shells grow in three dimensions; you would not see this obvious layering in actual turtle shell nails.
Not all man-made nails have this but you can be sure no turtle shell nails do.
4: Ultraviolet / Black Light Florescence
So let’s say the pattern looks realistic, there are no microcracks, and you can’t see any layers. How can you test the nails now? Put them in a dark room and expose them to ultraviolet / black light.
Many materials glow with strange colors when exposed to ultraviolet or black light. What is happening is the black light strikes the material with ultraviolet, invisible light (in addition to the purple). Special particles in the nails called phosphors absorb that ultraviolet light as energy, and use that energy to emit their own light of a different color.
Animal materials such as teeth, horn, shell, and tusk ivory have similar phosphors and thus emit a similar color. Man made materials emit an entirely different color.
The first photograph shows four nails. The top two are Nylon, left; Ox horn, Right. The bottom two are Imitation turtle shell, left; Real turtle shell, right. Notice how the nylon and imitation nails are dominated by this purple shade while the real ox horn and real turtle shell have a green-ish cast. That is a strong indicator that the material was grown by an animal, not man made.
The second photo was shot with a special color balance to hide the purple light. The resin nail, at left, has a duller color and its dark areas turn yellow/brown. The turtle shell nail, right, fluoresces with a brighter light and its dark areas show closer to black. The colors in this photo are closer to what the human eye perceives. Digital cameras are not quite able to show both the yellow, green, and purple all at once.
The black light used was a handheld flashlight purchased from a local hardware store. You can use similar devices as long as they emit UVA. (Fun fact: JB purchased that light minutes before crossing an international border in a desperate attempt to determine if the guzheng he was transporting contained ivory. Thankfully it did not.)