Which variety of tourmaline is known to be the most expensive?

The most expensive variety of tourmaline is actually known to be the rubellite. Rubellite is characterized by its rich pink to red hues, which are highly sought after in the gemstone market. Its vibrant color and rarity contribute to its high value.

While the copper-bearing variety of tourmaline is distinctive and can command high prices due to its unique colors, it does not surpass the value of rubellite on average. Other varieties like indicolite, which is valued for its blue color, and green tourmaline, while also beautiful, generally do not reach the same price points as rubellite. Consequently, rubellite's combination of color, demand, and rarity solidifies its status as the most expensive among tourmalines.