Deep red garnet is derived from a number of minerals, including pyrope and almandine. Popularized in Bohemia in the Czech Republic, garnet has been used in decoration and jewelry across Europe for many years. Its color is generally a dark burgundy, sometimes with a hint of orange, pink, or purple.
Opals form when silica gel hardens in the cracks of other rocks. Most of the world's precious opal comes from Australia, where opal is the national gem. A boulder opal is an opal that has been sliced together with its surrounding ironstone for a varied look. Fire opal from Mexico comes in shades of orange and Peruvian opal is an opaque blue-green stone. An opal doublet has polished precious opal on the top with an ironstone backing added for strength, making the slice of opal less prone to chipping.
Rose quartz can range from very pale pink to an almost cotton candy color and from nearly transparent to a milky opaque. Believed by some to represent love and healing, rose quartz is almost always found in large masses but rarely in crystals. Brazil, Sweden, Scotland and California all have significant deposits of rose quartz.
Tourmaline is a coveted stone that comes in a wide range of colors from black to pink, green and blue. Crystals which display more than one color together are common. A cross-section of a watermelon tourmaline crystal reveals green on the outside and pink within.