Kyanite is an aluminum silicate mineral found in metamorphic rocks. Its vibrant blue variety is prized for its distinctive bladed crystal structure and variable color intensity, ranging from pale sky blue to deep, saturated indigo. This coloration arises from trace amounts of iron and titanium within the crystal lattice. Key characteristics include perfect cleavage in two directions and notable anisotropism, meaning its hardness differs depending on the direction of the scratch.
Historically, kyanite’s heat resistance has led to its industrial application in high-temperature ceramics and refractories. The aesthetic appeal of the blue variant has also made it a popular gemstone, believed by some to enhance communication and tranquility. Its anisotropic nature presents lapidary challenges, requiring careful cutting and polishing to maximize brilliance and durability.