Step 2: Advanced Gemology

Lesson 7

Is Gemstone Radiation Safe?

Most gem buyers will accept that heat transforms brown zoisite to blue tanzanite and purple quartz (amethyst) into yellow quartz (citrine). The gem industry has used heat enhancement for many years. On the other hand, gem dealers worry that an ill-informed public would refuse to buy jewelry containing irradiated stones. Of course, gemstone radiation poses no health risks as long as the process is carefully controlled.

What is Radiation?

The term “radiation” covers a number of phenomena which fall into two groups: electromagnetic and particulate.

Electromagnetic Radiation

Radio waves, microwaves, and visible light are the most well-known forms of electromagnetic radiation. These all consist of photons, or small “clumps” of vibrating electric and magnetic fields, moving through space at light speed. The faster the vibration, the more energy (and smaller wavelength) a photon has.

Visible light vibrates at a mere 1014 times per second and has relatively low energy. As the frequency increases and the wavelength gets smaller, we pass through the ultraviolet spectrum, first to X-rays and then to gamma rays. These can have hundreds or thousands of times as much energy as visible light.…