Peridot
Peridot
Peridot is a gemstone derived from olivine, a mineral abundant in the Earth's mantle, making it a fascinating stone for connecting jewelry and deep geology. Its green color, often vibrant and "lime," is primarily due to the iron naturally present in its crystalline structure: unlike many gemstones, it does not require rare impurities to be colored. Peridot crystallizes in an orthorhombic system and forms in igneous rocks such as basalts, but also in certain mantle rocks brought to the surface. It is also found in pallasite meteorites, where olivine appears as green inclusions within a metallic alloy, a direct link between terrestrial mineralogy and extraterrestrial materials.
With a hardness of approximately 6.5 to 7 on the Mohs scale, it is quite durable, but it remains susceptible to impacts and scratches if handled carelessly. It sometimes displays small "lily pad" inclusions, typical internal patterns created by healed microfractures, prized by gemologists for identification. Optically, peridot can exhibit slight pleochroism, with shades ranging from yellowish-green to a brownish-green depending on the viewing angle. Its hue also depends on its iron content: the higher the iron content, the deeper and slightly darker the green can become. The finest specimens possess beautiful transparency and a vitreous luster, enhanced by precise cutting that maximizes light.
For maintenance, gentle cleaning with warm soapy water is recommended, avoiding ultrasound, steam, and harsh chemicals. Peridot is thus a stone that is both luminous and "scientific": a fragment of the Earth's mantle, and sometimes even of space, transformed into a brilliant gem.