About Gemstones

Some Basic Information

Rocks

Rocks are naturally occurring solid materials made of one or more minerals, and they make up much of the Earth’s crust. There are three main types of rocks: igneous rocks, which form when molten rock cools and hardens; sedimentary rocks, which form from layers of sediment pressed together over time; and metamorphic rocks, which form when existing rocks are changed by heat and pressure.

Chemicals and Gemstones

Chemicals help make different gemstones because each gemstone has its own chemical composition, which means it is made from a particular combination of elements. Small amounts of extra elements, called impurities, can also change a gemstone’s colour. For example, chromium can make some gemstones red or green, while iron can create yellow, brown, or purple colours. This is why gemstones that look different can form in different ways even when they grow in similar conditions.

Natural Gemstones

Natural gemstones are stones formed naturally deep within the Earth over millions of years through heat, pressure, and other geological processes. They are highly valued because each one is unique, often containing tiny natural markings known as inclusions that show how they developed. Gemstones are prized for their beauty, durability, and rarity, with features such as colour, shine, and strength making them desirable for jewellery.

They can form in different ways, including from cooling molten rock, from minerals dissolved in water filling cracks in rocks, or through intense pressure underground. Some gemstones, like pearls and amber, are even formed from organic materials rather than minerals.

Dyed Gemstones

Dyed gemstones are natural stones that have been treated with artificial colour to improve or change their appearance. This process involves adding dyes or pigments into the stone, often by soaking it in a coloured solution so the colour penetrates pores, cracks, or tiny spaces within the gemstone. Dyeing is commonly used to enhance dull or pale stones, create brighter and more uniform colours, or even imitate more expensive gemstones. Stones such as agate, jade, turquoise, and quartz are often dyed because they can absorb colour easily.

While dyed gemstones can look very attractive and are usually more affordable, the colour may sometimes fade over time or with exposure to light, heat, or chemicals, which can affect their value. Because dyeing is a treatment, it is important that sellers clearly state when a gemstone has been dyed so buyers understand what they are purchasing.

Imitation Stones

Imitation stones are materials that are made to look like real gemstones but are not actually the same in composition or origin. They are created from substances such as glass, plastic, or other minerals to copy the colour and appearance of natural gems, often at a much lower cost. Unlike natural or even synthetic gemstones, imitation stones do not have the same physical or chemical properties as the real stone they resemble. They are mainly used in costume jewellery because they are inexpensive and easy to produce.

Synthetic Stones

Synthetic stones, also known as lab-created or man-made gemstones, are stones that are produced in laboratories rather than being formed naturally in the Earth. They are created using advanced technology that copies the natural conditions of heat and pressure, allowing crystals to grow in a controlled environment. Unlike imitation stones, synthetic gemstones have the same chemical, physical, and optical properties as real natural gemstones, meaning they are considered genuine stones, just with a different origin. Synthetic stones are often clearer, more uniform in colour, and much more affordable because they can be made in large quantities in a shorter time.

Overview

Gemstones can be classified into several different types based on their value and how they are formed, including precious, semi-precious, and organic gemstones, as well as natural, synthetic, imitation, and treated stones. Precious gemstones such as diamonds, rubies, sapphires, and emeralds are rare and highly valuable, while semi-precious gemstones like amethyst and topaz are more common but still widely used in jewellery. Organic gemstones, such as pearls and amber, come from living organisms.

Common Gemstone Families

Jaspers

Jasper is a semi-precious gemstone that belongs to the quartz family and is known for its opaque appearance and wide variety of colours and patterns. It is a microcrystalline stone, meaning its crystals are very small, which gives it a smooth and solid look. Jasper can be found in colours such as red, yellow, green, and brown, often with unique spots or stripes. It forms naturally in the Earth over time and is widely used in jewellery and decorative items because it is durable and attractive.

Jades

Jade is a semi-precious gemstone that is well known for its smooth texture and wide range of colours, especially green. It is not a single mineral but a name for two types of gemstones called jadeite and nephrite, with jadeite being rarer and more valuable. Jade has been used for thousands of years to make jewellery, carvings, and decorations because it is very tough and durable. It is also an important stone in many cultures, symbolising beauty, strength, and good fortune.

Agate

Agate is a semi-precious gemstone that belongs to the quartz family and is a variety of chalcedony. It is easily recognised by its unique banded patterns, which are formed by layers of minerals building up over time inside rocks. Agate can appear in many different colours, including red, blue, brown, and yellow, and each stone is different in its design. It forms naturally when silica-rich water fills small spaces in rocks, creating layers that harden into beautiful patterns. Because of its durability and attractive appearance, agate is commonly used in jewellery and decorative objects.

Quartz

Quartz is a very common mineral made of silicon dioxide and found in many types of rocks and environments. It is known for its hardness and durability, making it resistant to weathering and damage. Quartz can be clear or come in a wide range of colours due to impurities, and many gemstones such as amethyst and rose quartz are varieties of quartz. Because it is strong and widely available, quartz is used in jewellery, construction materials, glass production, and electronic devices.

Obsidian

Obsidian is an extrusive igneous rock that forms when lava cools very quickly at the Earth’s surface, creating a smooth, glass-like material known as volcanic glass.