Amblygonite are beautiful mint aqua gemstones from Brazil’s Morro Redondo Mine. A decade ago, Amblygonite was limited to specialist gem/mineral collections and museums. Thankfully, relatively new chance discoveries in Brazil have brought this beautiful, incredibly rare, exotic gemstone out of glass cabinets and into jewelry.
Refractive Index 1.578 – 1.646
Relative Density 3.01 – 3.11
Usually white, cream or pastel yellow, Amblygonite’s most prized color is an unusual and highly desirable mint aqua; pastel to medium toned bluish-greens to greenish-blues, sometimes with hints of lime. This unlikely, but beautiful color accentuates both its rarity and appeal, possessing visual similarities to Apatite, Beryl, Hiddenite, and Paraíba Tourmaline. Amblygonite is very challenging for the lapidary due to four different directions of cleavage at different angles from one another, all with varying qualities. Despite these challenges, Amblygonite is finished eye-clean, the highest quality clarity grade for colored gemstones, displaying a desirable even color, good brilliance, high luster, and excellent scintillation (play of light).
Amblygonite (pronounced Am-Blig-O-Night) is a fluorophosphate mineral, composed of aluminum, fluoride, hydroxide, lithium, phosphate, and sodium. The mineral was first discovered in Saxony, Germany by August Breithaupt in 1817, and named by him from the Greek ‘amblus’, meaning blunt, and ‘gouia’, meaning angle, because of the obtuse (i.e. slightly differs from 90°) angle between its cleavages. This distinguishes it from similar appearing gems such as Apatite, Beryl, Hiddenite, Quartz, Scapolite, and some Feldspar. Later it was found at Montebras, Creuse, France, and at Hebron in Maine, USA. Because of slight differences in optical character and chemical composition the names Montebrasite and Hebronite have been applied to the minerals from these deposits. Amblygonite is generally white, cream or pastel yellow, but can also be beige, blue, colorless, green, grey, pink, or purple. The mineral occurs in pegmatite deposits with Apatite, Spodumene, Tourmaline and other lithium-bearing minerals. As a mineral, Amblygonite contains about 10 percent lithium and has been used as a source of lithium.
Extremely rare, transparent Amblygonite has been faceted and used as a gemstone. The main, albeit sporadic, sources for gem-quality Amblygonite are Brazil and the USA. Australia, Burma, France, Germany, Namibia, Norway and Spain have also produced gem quality Amblygonite, but not in commercial quantities. Our Amblygonite is from the Morro Redondo Mine near Coronel Murta in the Brazilian state of Minas Gerais (English: General Mines). This gemstone and specimen mine works a pegmatite found in 1991 measuring 400 meters in length with an average thickness of 30 meters, noting our gems are historic production, there has been no significant Amblygonite output from this mine for several years. Apart from its geological scarcity and prized hue, Amblygonite is also a challenging gem to cut further accentuating its rarity.
Durability & Care
Amblygonite (Mohs’ Hardness: 6) is an excellent collector’s gemstone. Always store Amblygonite carefully to avoid scuffs and scratches. Clean with gentle soap and lukewarm water, scrubbing behind the gem with a very soft toothbrush as necessary. After cleaning, pat dry with a soft towel or chamois cloth.