These rubies range from 20 to 100 mm across the pinacoidal face, with the length across the prism faces varying from 10 to 50 mm. They have a maroon color, and some show 16 mm dot inclusions of hematite. The stones are mainly hexagonal but come in many sizes and shapes. In the town of Subramaniam, close to Madikeri, large hexagonal pillars of ruby are mined deposits are also located in the nearby villages. A ruby-bearing granulite, commonly called ruby rock, is used for making artifacts such as wands and crystal balls. The ruby found here is lighter, translucent to transparent, and of good quality.
Madikeri is a remote hill station covered by lush green forests, located in the Western Ghats of India. The mines situated in Karur are located on barren land along the roadside the nearby towns of Kangayam and Paramatti also have ruby mines. Good-quality transparent rubies come from the Karur region, though color varies along this gemstone belt. In all of these locations, mining is performed using primitive methods. Channapatna (figure 1, top left), roughly 280 km (117 miles) from Madikeri, is famous for its star rubies. Ruby is also found in Subramaniam (also known as Red Hills), near Madikeri in Karnataka. The city of Karur itself is well known for rubies. The Karur-Kangayam and Hole-Narsipur belts, in the southern Indian states of Tamil Nadu and Karnataka, respectively, are famous throughout the subcontinent for their gemstones, including sapphire, moonstone, iolite, aquamarine, garnet, sunstone and corundum. Photomicrographs by Pooja Shirole crossed polarizers, magnified 4×. Bottom right: A corundum granulite showing ruby with blue and pink interference colors. Bottom left: This thin section of ruby is surrounded by an isotropic reaction rim. Top right: This 15 kg rough ruby is from Subramaniam, in the Indian state of Karnataka. Top left: Rubies are mined in a mango orchard in Channapatna, India. Manage Your GIA Alumni Association™ Membershipįigure 1. Comprehensive CAD/CAM For Jewelry Certificate