Following its discovery in Sri Lanka, sinhalite’s olivine-like optical and physical properties initially led mineralogists to believe it to be a brownish variety of peridot. However, it was eventually determined that the crystals in fact belonged to a new mineral species, which came to be named after the Sanskrit word for the island upon it was first found, Sinhala. A few years later, a second source of facet-quality material was discovered within Myanmar’s famous Mogok gemstone tract, while pinkish crystals have also recently been reported from Tanzania.
In nature, sinhalite is almost always encountered in the form of rounded, water-warn pebbles, rather than a recognizable surviving crystal habit. As a result, rough material is usually identified by way of its distinctive absorption spectrum, which possesses four bands in the cyan/blue region as opposed to peridot’s three.