any gemstones that is not a diamond, ruby, emerald or sapphire is a semi-precious gemstone. Calling a gemstone semi-precious does not mean it is less valuable than precious gemstones. Semi-precious gemstones are just usually more abundant (but there are a few exceptions).
The value given to semi-precious gemstones depend largely on color, durability and quality. Because these gemstones typically have more sources, they are a good choice for larger, clean-eye stones and come in a rainbow of colors.
Some semi-precious gemstones are not stones at all, but are made of organic material like amber, coral and pearl. This guide will reveal details about some of the most popular semi-precious gemstones – garnet, peridot, amethyst, citrine, blue topaz and turquoise. For information on the only semi-precious gemstone that comes from an organism.
Amethyst (1)Amethyst is a violet variety of quartz often used in jewelry. The name comes from the ancient Greek méthystos ("intoxicated"), a reference to the belief that the stone protected its owner from drunkenness. The ancient Greeks wore amethyst and made drinking vessels decorated with it in the belief that it would prevent intoxication. It is one of several forms of quartz. Amethyst is a semiprecious stone and is the traditional birthstone for February.
Catseyes (1)Translucent yellowish chatoyant chrysoberyl is called cymophane or cat's eye. Cymophane has its derivation also from the Greek words meaning 'wave' and 'appearance', in reference to the haziness that visually distorts what would normally be viewed as a well defined surface of a cabochon. This effect may be combined with a cat eye effect. In this variety, microscopic tubelike cavities or needle-like inclusions of rutile occur in an orientation parallel to the c-axis, producing a chatoyant effect visible as a single ray of light passing across the crystal. This effect is best seen in gemstones cut in cabochon form perpendicular to the c-axis. The color in yellow chrysoberyl is due to Fe3+ impurities. Although other minerals such as tourmaline, scapolite, corundum, spinel and quartz can form "cat's eye" stones similar in appearance to cymophane, the jewelry industry designates these stones as "quartz cat's eyes", or "ruby cat's eyes" and only chrysoberyl can be referred to as "cat's eye" with no other designation. Gems lacking the silky inclusions required to produce the cat's eye effect are usually faceted. An alexandrite cat's eye is a chrysoberyl cat's eye that changes color. "Milk and honey" is a term commonly used to describe the color of the best cat's eyes. The effect refers to the sharp milky ray of white light normally crossing the cabochon as a center line along its length and overlying the honey-colored background. The honey color is considered to be top-grade by many gemologists but the lemon yellow colors are also popular and attractive. Cat's eye material is found as a small percentage of the overall chrysoberyl production wherever chrysoberyl is found. Cat's eye really became popular by the end of the 19th century when the Duke of Connaught gave a ring with a cat's eye as an engagement token; this was sufficient to make the stone more popular and increase its value greatly. Until that time, cat's eye had predominantly been present in gem and mineral collections. The increased demand in turn created an intensified search for it in Sri Lanka.
Citrine (2)Natural Citrine is a premier stone of manifestation, imagination, and personal will. Carrying the power of the sun, it is warm and comforting, energizing and life giving. It stimulates the chakras like the sunlight of spring, clearing the mind and stirring the soul to action. Its frequency awakens creativity and imagination, and sustains the process of transforming dreams and wishes into tangible form. With its pure yellow energy, Citrine encourages fullness of life, fresh beginnings and new pursuits. Natural Citrine does not hold or accumulate negative energy, but rather transmutes, dissipates, and grounds it, making it extremely protective for the environment. It works out problems on both the physical and subtle levels, transforming negative thoughts and feelings into positive ones. It is one of only two crystals on Earth that never needs to be cleared or cleansed.
Quartz (1)Quartz is the second most abundant mineral in Earth's continental crust, after feldspar. Its crystal structure is a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. There are many different varieties of quartz, several of which are semi-precious gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz belongs to the trigonal crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end. In nature quartz crystals are often twinned, distorted, or so intergrown with adjacent crystals of quartz or other minerals as to only show part of this shape, or to lack obvious crystal faces altogether and appear massive. Well-formed crystals typically form in a 'bed' that has unconstrained growth into a void; usually the crystals are attached at the other end to a matrix and only one termination pyramid is present. However, doubly terminated crystals do occur where they develop freely without attachment, for instance within gypsum. A quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward.