What are precious and semi-precious gemstones?
This a frequent question amongst people interested in gemstone jewellery. For some gemstone preference is simply based upon colour but if you would like to understand more before making your choice read on for further insight!
Precious and semi-precious gemstones are both classifications of gemstones. In the 1800s, gemstones were divided into 2 categories: precious and semi-precious, depending on the considerations of their difference in value at the time. Today, value parameter is not the main factor, or only criteria, in which a stone is evaluated against. The quality, rarity and provenance are all taken into consideration.
What are the differences between precious and semi-precious gemstones?
Original categorisation, dating back to the late 18th Century, was initially based on the rarity of the stone itself. Stones that were plentiful were considered to be semi-precious, and those that were rarer were classed as precious.
The separation between precious and semi-precious gemstones has no specific scientific backing. When the categorisation was initially founded, it was mainly due to the value, rarity and demand at that time. Perception amongst most buyers is that having a ring showcasing a precious stone is far more valuable. But nowadays, there are a number of factors that determine the value of a stone, such as durability, hardness and beauty.
It is important to consider, though, that just because a stone is not classified as precious, it does not mean that it is inferior or less valuable. In some circumstances, there is the possibility that a semi-precious gemstone can be worth much more than a precious stone. For example, due to the way pearls are cultivated, natural pearls tend to garner huge prices, sometimes even worth more than a low quality precious stone.
This extends to many other semi-precious stones. They may be harder to find, or more difficult or expensive to mine, and they may even be produced in much lower qualities. So, they could become rarer than the precious stones, and therefore, sold at a much higher price.
The 4 precious gemstones
The precious gemstones are Diamond, Emerald, Ruby and Sapphire. These four stones, also known as ‘the big four’, have generally been the most expensive and wanted, and are distinguished by their quality, their rarity, and the beauty of their colours.
The characteristics that make the four precious stones so valuable are the clarity and the hardness of the stone. They can be exceptionally clean, with no impurities inside. The hardness of the precious gemstones ranges from 7.5 - 10, the last highest levels of the Mohs scale.
Precious stones also have unique characteristics such as brightness, excellent light dispersion and scintillation, an unmatched fire, and vivid colours. All keeping with the common feature of hardness, and their ability to withstand scratching.
High quality, genuine stones, as well as gemstone jewellery pieces, are hallmarked, and are sometimes accompanied by certification. Stones are tested and graded by professional gemologists against specific criteria, such as those set out by the GIA, and are tested by advanced equipment.
With a hardness level of 10, diamond is considered to be the hardest natural mineral on the Earth. In fact, only another diamond can scratch another diamond! They are also the highest valued precious stone, due to the way they are formed, as well as their unrivalled, exceptional characteristics such as strength and beauty.
The ruby is well known for its deep, beautiful red colouring, prized for its hardness, durability and lustre. Colour is the most significant factor in determining a ruby’s value, those with a pure red hue having the highest prices.
Mined within the depths of South America, emeralds are renowned for their unique, exquisite green colour. This colour is provided by the element Chromium, and in terms of the value of the stone, it is typically that the deeper the colour of the emerald, the higher its value. The surface of an emerald is very brittle, and therefore, can make it difficult for jewellers to fashion them into shapes that are required for jewellery pieces, meaning that they can become pricey.
Sapphires are the most valuable, and rarest, blue coloured natural gemstone. They are highly desirable due to their strong, vivid colour saturation, and their velvety, royal blue colour. Sapphires are also second on the scale, after diamonds, for their hardness and durability. The sparkle from the light performance within this gemstone is of the highest quality, producing a beautiful, unmatched lustre. Sapphires are also unique in the way that they are available in many different colours such as pink, orange, yellow, purple and black. Sapphires feature in some of the most iconic and familiar gemstone jewellery pieces, for example Princess Diana's engagement ring.
The semi-precious gemstones
Simply put, semi-precious stones are said to be any other gemstones than the four precious gemstones. The most well-known semi-precious gemstones are Topaz, Citrine, Pearl, Aquamarine, Amethyst and Tanzanite. The most expensive is alexandrite, their prices even reaching higher than that of a precious stone at times.
What makes these stones stand out as semi-precious is the difference in transparency, in that they can be opaque, even having visible inclusions. This is because many semi-precious gems can be represented by rocks or organic material such as minerals. Therefore, they have colours that are not typical for precious stones, such as yellow and purple.
Unlike precious stones, most semi-precious gems are soft, their hardness scattered across the whole Mohs scale. This low hardness allows for semi-precious gemstones to be suitable for cutting, carving and adornment, and to craft decorative items such as vases and cameo jewellery.
What is birthstone jewellery?
A birthstone is a gem that corresponds to your month of birth. Each one has a different meaning, rooting back to ancient myths and beliefs. Birthstone jewellery pieces are often bought as presents and gifts, due to their sentimental meaning and value, as well as their irresistible beauty. Precious and semi-precious stones are often used within this jewellery, making for unique, stunning pieces that stand out to each person individually.
At Sonny's Jewellers, we have a wide selection of gemstone jewellery, including coloured stone rings, earrings, pendants and more. Browse today and find the birthstone that is right for you!