Their prices are much lower than the prices for fine green tourmaline or brighter bluish green tourmaline. Blue tourmaline can range in tone from light to dark. The hue is often modified by green so ...

Figure 1. This specimen of dark blue tourmaline on micaceous matrix, from the Koksha Valley of Badakhshan Province in Afghanistan, measures 28 × 25 × 17 mm. Photo by Kevin Schmacher. Around a dozen ...