Infrared Light
The sun is the most natural source of heat. More than half of the solar energy that reaches Earth is in the form of infrared (IR) light. Infrared radiation lies just beyond the red edge of the visible spectrum. As frequency decreases, wavelength increases — from about 0.75 microns up to about 1000 microns.
Infrared light is a form of radiant heat. It has lower frequency and longer wavelengths than visible light, and higher frequency and shorter wavelengths than microwaves.
Industry standards usually divide infrared into three general bands:
- Far infrared (FIR): ~8–1000 microns
- Mid infrared (MIR): ~1.4–8 microns
- Near infrared (NIR): ~0.75–1.4 microns
Near infrared is closest to visible light. Far infrared lies farthest from the visible spectrum and closer to the microwave region.
Although the human body naturally emits mostly in the mid-infrared range (roughly 2–10 microns), longer-wave far-infrared energy is absorbed efficiently by the body’s surface layers and is often perceived as gentle, deep warmth. FIR is also easier to sense than NIR, which helps reduce the risk of overheating during normal use.
Far infrared is sometimes described as “nature’s most comfortable heat,” because it transfers warmth without visible light or ultraviolet radiation.
The technology behind FIR heating systems was first explored and developed decades ago, most visibly in FIR sauna applications, and is now used in many wellness products around the world.
In Ereada® mats, far-infrared heat is refracted and distributed through multiple layers, including bamboo charcoal, yellow clay, and — most importantly — natural tumbled gemstones such as amethyst, tourmaline, jade, and agate. These stones help spread the heat evenly across the surface.
Why amethyst is often highlighted
When we say that amethyst acts like a “conductor” of infrared heat, we do not mean it in the strict physics sense. The term refers to the stone’s ability to absorb heat and then re-emit it in a comfortable FIR/MIR range suitable for mat technology. Amethyst also works in synergy with other layers and stones in the mat.
Ereada® Amethyst Mats emit both FIR and MIR heat, with high efficiency in the commonly referenced 4–16 micron range.
Green jade is also valued for its infrared-emission properties and is used in some mat designs.
(Testing such as that performed by Korean laboratories has shown strong FIR output values under controlled conditions.)