Precious stones
Gemstones are a type of expensive minerals, and they consist of the crystallization of one metal and more. This crystallization results from the exposure of some materials and some minerals and organic materials to pressure and heat over the years. It is important to know that there are many types of gemstones on the surface of the Earth, and these stones differ. Among them, based on the nature of the materials that make them up, and based on the degree of clarity, size, and shape. Gemstones have many uses, including decorative uses, therapeutic uses, and others.
How are gemstones formed?
Most gemstones form in the Earth's crust, approximately 3 to 25 miles below the Earth's surface. Two gemstones, diamonds and aquamarines, are found much deeper in the ground. Diamonds form in “kimberlite pipes” that originate in the Earth's mantle (>125 miles) and terminate at the surface. Molten material that passes through these tubes often reaches the surface as lava and cools, but if it does not reach the surface, it cools slowly, crystallizes, and forms rough, granular minerals.
Types of gemstones
There are several types of gemstones, including:
- Yemeni antique, also called onyx. This type of gemstone is a chemical compound consisting mainly of silica and some impurities such as iron compounds. This stone has many colors, including yellow, red, and brown, but its most famous type is the brown antique, which is called hepatic and antique. The red color called pomegranate.
- Topaz is called yellow sapphire, or yellow sapphire. This stone is formed in the heart of the cavities of stones such as hard schist and the heart of granite stones. It is available in several colors, including brown, blue, yellow, and golden yellow, and this color is considered the most common for this stone.
- Peridot is characterized by its radiance and splendor. This stone is clear and does not contain yellowness or blackness. It is available in several colors, but the most common are Cypriot yellow and Egyptian green.
- Pink quartz. There are two types of this stone: limestone, which has a white color, and potash, which has two colors, pink and white. Pink quartz has more regular crystals compared to other precious stones, and it is also available in larger sizes.
- Lapis lazuli, which was called lazuli, is characterized by its dark blue color. It is widely found in Iran and consists of dual chemical compounds of sodium and aluminum silicates, as well as a mixture of sulfur and iron.
- Amethyst, also called the Oriental Ruby, is composed of some manganese, and this element gives it the violet color in both dark and light shades. It is also available in purple, and colors extending from violet to violet.
- Jasper is distinguished by its purity, transparency and high quality.
- Beryl, called the Egyptian emerald, because it is widely found in Egyptian mines. It is distinguished by its transparency, hexagonal-shaped crystals, and its double composition combining aluminum silicates and beryllium. It is available in several colors, including blue and light bluish.
- Star sapphire is characterized by its white lines, and this stone can be completely transparent or semi-transparent.
- Al-Safir, this stone is formed as a result of a type of corundum mineral being exposed to intense pressure and high temperature. This stone is available in many colors except red, but the most expensive of them is transparent blue.
