The listing, Handmade Mexican Hemp Bracelet w/ Fire Agate and Sterling Silver has ended.
Hemp bracelet with Mexican fire agate and sterling silver 925
What is Fire Agate?
Fire agate is a brown, microcrystalline quartz (chalcedony) which has a botryoidal (grape-like) growth form, and which contains layers of plate-like crystals of iron oxide (limo-nite) in various planes within it. The layers are small enough that light entering them forms interference colors known as "fire." The iridescent colors of red, gold, green and rarely, blue-violet, result from interference between diffracted light rays traveling through and reflecting off of these thin layers. (We see the same effect when looking at the rainbow colors at the surface of an oily puddle of water; or in the "orient" created by the layers of nacre on the surface of pearl.) Looking at a fire agate is much like looking down into the burning embers of a fire, which is exactly how it got its name. The gem is thought to be formed when hot water saturated with colloidal silica and iron oxide invades cavities in country rock and begin to cool. Chalcedony with iron oxide begins to grow on any available surface (the iron oxide gives the basic brown color to the gem). As the solutions began to precipitate and grow layers of silica and iron oxide would be deposited depending on the relative level of those elements in solution and underlying conditions. These alternating silica and iron oxide layers (Schiller layers)) cause the brilliant fire in the gem. As iron oxide ran out in the solution colorless chalcedony continued to grow.
Sources: answers.com; www.crystalwellbeing.co.uk; bwsmigel; wikipedia.org; yourgemologist.com