* Gold's Inert Nature: Gold is chemically inert. It doesn't readily react with other substances. Makeup and toothpaste are designed to clean and enhance appearance, not to react with or dissolve metals.
* Lack of Reagents: Makeup and toothpaste do not contain the necessary reagents (chemicals) to dissolve gold or to indicate its presence through a color change or other observable reaction.
* Interference: The various ingredients in makeup and toothpaste would likely interfere with any potential reaction, making it impossible to see if any gold were present, even if a reaction were possible.
* Concentration Issue: Even if there were a trace amount of gold present, the concentration would likely be too low to detect using such crude methods.
Reliable Methods for Gold Testing:
To accurately test for gold, you need specialized equipment and chemicals. Here are some common methods:
* Acid Test: Using acids like nitric acid and hydrochloric acid (aqua regia). Gold is resistant to most acids, but aqua regia can dissolve it.
* X-ray Fluorescence (XRF): A non-destructive method that analyzes the elemental composition of a material.
* Fire Assay: A destructive method that involves melting the sample and separating the gold.
* Electronic Gold Testers: These devices measure the electrical conductivity of the metal.
In summary, using makeup or toothpaste to test for gold content is not scientifically sound and will not provide accurate results.