Garnet
Garnet
Garnets do not refer to a single stone, but to a family of minerals with similar compositions, which explains their wide range of colors. They often form during metamorphism, when heat and pressure transform rocks deep within the Earth, but they are also found in some igneous rocks. Their hardness generally ranges from 6.5 to 7.5 on the Mohs scale, making them suitable for jewelry, with good resistance to wear. The best-known variety is almandine, a deep red, but there is also pyrope (intense red), spessartine (orange to reddish-orange), and grossular, which can range from green to yellow.
Among green garnets, tsavorite (a bright green grossular) is highly prized for its brilliance and emerald color. There is also andradite, whose famous demantoid variety is distinguished by its very strong luster and sometimes by characteristic fine "horsetail" inclusions. Some varieties, such as rhodolite garnet, offer raspberry to purple hues thanks to natural mixtures between garnet species. From a scientific point of view, color and properties change depending on the elements present (iron, magnesium, manganese, chromium), which modify light absorption. Garnets are also valued because they generally have little cleavage, making them less fragile than other gemstones. Ultimately, choosing a garnet means choosing a stone with multiple "personalities": a single mineral family, and a palette of varieties ranging from classic red to the rarest greens.