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Precious & Semi-Precious Gemstones: Explanation & Difference

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Precious and semi-precious stone terms are surrounded by feelings of beauty, brilliance, and wealth. Precious stones used to be the biggest treasure people can imagine. The article describes which gemstones are considered precious or semi-precious and why. You will discover the difference between the terms precious and semi-precious, along with the most beautiful examples and answers to the most popular questions.

The main difference between precious and semi-precious stones is that there are only four precious stones. They are diamond, ruby, emerald, and sapphire. Any other gemstone is considered to be semi-precious. However, gemologists suggest using this classification very carefully as it is a bit outdated nowadays.

What characteristics make precious stones so different from others? How to identify precious stones, and how many precious stones are there? Where to buy and how to store precious and semi-precious stones. Keep going, and you will get responses to these questions and even more!

What Are Precious Gemstones & How to Identify Them?
What Are Precious Gemstones & How to Identify Them?

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What Are the Precious Gemstones?

Precious gemstone is something bright, sparking, and almost magical. Every time we hear a precious stone, we imagine the rarest and the most beautiful treasure of bright green, red or blue color.

From ancient legends to contemporary novels, authors appreciate precious stones as something more valuable than money or gold. What are precious stones? Why they are so significant?

Precious stones are considered to be four gems (diamond, emerald, ruby, and sapphire).  Sometimes alexandrite, jadeite, and pearls can be added to the list. However, this classification is not documented. Most jewelry experts acknowledge this definition is a bit outdated and recommend using it with care. 

The division of gemstones into precious and semi-precious came from ancient times when gemological equipment was not so advanced, and people identified gems by color only. 

Since then, diamond – as the hardest, ruby as the most vivid red, sapphire as magnificent blue, and lush green emerald were the most highly praised. 

Other characteristics, which make the Big Four so valuable, are clarity and hardness. All these stones can be exceptionally clean, with no impurities inside.

The other significant characteristic is hardness. All three minerals are on the last highest levels of the Mohs scale. Emerald hardness varies from 7.5 to 8. Sapphires and rubies are two varieties of corundum which has 9 hardness on the scale.

Diamond is an absolute winner. Diamond hardness is 10, and it is considered to be the hardest natural material on Earth. Only a diamond can scratch another diamond. 

These precious stones were the main purpose of migration and war campaigns. They are the most valuable part of the monarchs’ collections.

For centuries people knew that diamond, emerald, sapphire, and ruby are the rarest, and that’s why the most expensive material. So now it’s just a habit to separate gemstones this way. 

How to Identify Precious Gemstones?

Precious stones are the most valuable natural material. The Big Four precious stones (diamond, ruby, sapphire, emerald) have very specific characteristics they are praised for.

Precious stones (diamond, emerald, ruby, and sapphire) possess unique characteristics. It is a brightness, scintillation, and fire for diamonds and vivid colors for others. Pigeon blood color for ruby, royal blue for sapphire, and lush green for emerald. The common feature for all is great hardness.

The highest quality precious stones are usually accompanied by certificates from the most reliable gemological laboratories nowadays. The stone was already tested by advanced equipment and the highest-ranked professionals. 

The common feature of all precious stones is their exceptional clarity, vibrant color, fire brilliance, and ability to withstand scratching (hardness above 8 on the Mohs scale).

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How Many Precious Gemstones Are There? List of Precious Gemstones

There is a slight misunderstanding in the modern classification of gemstones. The precious/semi-precious classification is believed outdated, and today there are no strict rules on which gem has to be considered precious or not.

The traditional perception of the precious stones term stands for only four gemstones, which are diamond, ruby, sapphire, and emerald. Jade, pearls, and alexandrite are sometimes listed additionally.  Modern gemmology lists around 300 gemstones without separation into precious and semi-precious stone groups.

A reasonable question can arise from your side. So what is the modern classification of gemstones? Unfortunately, there is no multifunctional classification of gemstones. There are some reasons for it we will shed light on. 

Precious and semi-precious groups were used since antiquity when the main characteristic of gemstones was color. It led to some huge inconsistencies, for instance, when spinel was commonly mistaken for ruby.

Another argument that this division is archaic is the price. Precious stones were considered to be the most expensive; however, some gems which are in the semi-precious group can be far more expensive and rarer than diamonds.

An additional reason for the mess above is that the gemstone itself is not defined precisely. Gemstone is considered to be a mineral, natural organic material (like pearls or corals) or rocks (lapis lazuli, charoite),  or mineraloids (opal) which are rare, durable, and beautiful.

Even if we close our eyes to organic material and the rocks present, the question of how we should measure beauty remains open. So an attempt to classify gemstones will be strongly dependent on a subjective understanding of beauty.

Gemologists and jewelry experts suggest using the term gemstone instead of precious or semi-precious stone. All gemstones are truly beautiful, and it’s impossible to make a quantitative determination if is it semi-precious or “quarter precious”.

Some experts differentiate gems into diamonds, colored stones, and organic gems. However, as usual, there are some exceptions.

The Gemological Institute of America suggests 29 gemstones in their gemstone encyclopedia. International Gem Society lists 304 gemstones in their encyclopedia

The World Jewelry Confederation attempted to put everything in order and published the CIBJO Blue Books, which are definitive sets of grading standards and nomenclature for diamonds, colored gemstones, pearls, coral, precious metals, and gemological laboratories.

There are no precious and semi-precious terms in there. Natural gemstones are subdivided into two groups:

  1. Inorganic Gem Materials 
  • Minerals – e.g. aquamarine, diamond, emerald, tourmaline, zircon, benitoite
  • Rocks – e.g. lapis lazuli, opal with matrix, and turquoise with azurite and malachite
  • Natural glass – e.g. obsidian and moldavite
  1. Organic/Biogenic materials 
  • Plant origin – e.g. amber
  • Animal origin – e.g. ivory, coral, pearl 

Here you may access the Gemstone Blue Book for more details.

TIP: The Internet is full of fake gemstones. You have to be careful when buying gemstones online. One of the common faked gemstones is lapis lazuli. Find out the differences between real and fake lapis lazuli in the article below:
Real vs. Fake Lapis Lazuli: Focus on These 6 Differences

How to Store Precious Gemstones?

Precious stones should be handled with care. Even if natural precious stones are on the top of the Mohs hardness scale, it doesn’t mean that they are indestructible. 

Speaking about diamond, ruby, sapphire, and emerald, all of them are above 7.5 on the Mohs scale. The main rule to storing precious stones is to keep them individually to avoid scratching. A special rule applies to emeralds because they are commonly fractured – ultrasonic cleaning is forbidden. 

Precious stones are extremely hard. It is a well-known fact that diamond is the hardest mineral in the world. No doubt it is true.

But the point is hardness and toughness are different physical properties. Precious stones are brittle. Diamonds cannot be scratched by a hammer but can be easily shattered into pieces.

That is why all gemstones should be carefully stored. The biggest attention should be paid to emeralds, pearls, opals, turquoise, and moonstone. Some gemstones can fade if exposed to light. The most subjected to fading are citrine, amethyst, and topaz. 

For more information on how to store your gemstones, please refer to the Gemological Institute of America’s recommendations (Link).

FAQ about Precious Stones

Still did not find the answer to your answers about precious stones? Find frequently asked questions in the section below:

Is a Rock Crystal Synonymous with a Precious Gemstone?

Absolutely not. Rock crystal is a transparent, colorless variety of quartz, while a precious gemstone is mostly applied to more expensive mineral species, such as diamond, ruby, sapphire, and emerald. Rock crystal refers to quartz only. Precious gemstones were applied to 300 gems.

What is the Most Precious Gemstone?

There is not just one. It depends on many factors, such as quality, durability, beauty, rarity, deposit, and market trends. Some people can name tanzanite, as it is quite popular and valuable now. In most cases, the most precious gemstone is a fancy-colored diamond, blue or red.

What is the Rarest Precious Gemstone?

The rarest precious gemstone is fancy-colored blue or red diamond. Because of the rarity, the price for 1 carat of fancy colored diamonds can go for more than $1,000,000. Sometimes tanzanite can be considered the rarest precious gemstone as it has only one supply source in the world.

What is the Most Expensive Precious Gemstone?

The CTF Pink Star (formerly The Pink Star and The Steinmetz Pink) weighs 59.60 carats (11.92 g), is the largest Internally Flawless Fancy Vivid Pink diamond, and the most expensive gemstone ever sold at auction. It set a new record on 3 April 2017 after being sold at an auction in Hong Kong.

TIP: Do you know what the rarest gemstones on the Earth are? You might be surprised to check the article below and find out what the 13 rarest gemstones are:
13 Rarest Gemstones on Earth: You will be Shocked!

What Are Semi-precious Gemstones?

What Are Semi-precious Gemstones & How to Identify Them?
What Are Semi-precious Gemstones & How to Identify Them?

If the stone is semi-precious, it doesn’t mean that it is not beautiful or rare. It’s a common thing that semi-precious stones can cost even more than precious.

This is one of the reasons why precious/semi-precious classification is not widely used now. But some people can still divide gemstones into groups, so we are going to help you understand them correctly.

Semi-precious stones were believed to be any other gemstone except precious stones (diamond, ruby, sapphire, and emerald). The most popular are topazes, tourmalines, garnets, alexandrite, amethyst, peridot, and many others. However, please, be careful, as this term is considered to be misleading now.

Semi-precious stones can be also subdivided into groups.

  1. Minerals:

Amethyst, topaz, garnets, tourmalines, agate, chalcedony, citrine, malachite, azurite, beryl, peridot, brazillianite, calcite, hematite, howlite, iolite, zoisite, zircon, sphalerite, celestine.

  1. Rocks and aggregates:

Lapis lazuli, charoite, turquoise, larimar, rhodochrosite, labradorite, sodalite, tiger’s eye, jadeite, jasper.

  1. Organic materials:

Amber, pearls, ammolite, and many others.

How to Identify Semi-precious Gemstones?

If you continue using precious/semi-precious classification, you can easily separate them one from another.

Semi-precious stones were believed to be any other gems than precious. They can have colors not typical for precious stones, like purple and yellow. Semi-precious gemstones can be opaque and can have visible inclusions. Semi-precious gemstones can be represented by rocks or organic material.

The main difference between precious and semi-precious stones was transparency. As some minerals from the semi-precious group are represented by mineral aggregates and rocks, they can be still suitable for cutting, curving, and adornment, but they are opaque or semi-transparent. 

Examples of such gems are turquoise, malachite, charoite, lapis lazuli, jasper, and many others. Sometimes the term decorative stones were also applied to opaque material.

Another significant difference between precious and semi-precious stones is hardness. Most semi-precious stones are soft. Semi-precious stones are distributed through the whole Mohs scale.

The low hardness allows them to carve semi-precious stones and make cameos, or table decorations, like ashtrays and vases.

And one more thing which allows identifying semi-precious stones is color. There are only four precious stones according to all classifications (diamond, sapphire, ruby, emerald), and all of them have their own unique color. The purple color of amethyst or charoite is not on the list. So this is a small hint for identification.

TIP: Mineral identification is an integral part of work for both mineral collectors and scientists. Check out the step-by-step guide on mineral identification in the article below:
Easy Step-by-Step Mineral Identification (Expert Explains)

Where Do Semi-precious Gemstones Come From?

Semi-precious stones cannot be counted precisely. They occur in any possible color, transparency, hardness, and form. They can be minerals or minerals (pyrope garnet) or mono-mineral aggregates (malachite).

Semi-precious stones can be represented by rocks (lapis lazuli, charoite). Some of them have an organic origin (amber, pearls, and corals).

Semi-precious stones come from all three possible types of geological formation: igneous, metamorphic, and sedimentary. Also, semi-precious stones can be not only minerals but also rocks and organic materials. So they usually come from any environment and can be found all over the world. 

Semi-precious stones can be found in river pebbles or in our backyard, so don’t miss the chance to find them. And remember, according to the new classification of the World Jewelry Confederation, you are encouraged to call all your findings a gemstone.

FAQ about Semi-precious Stones

Still did not find the answer to your answers about semi-precious stones? Find frequently asked questions in the section below:

What is the Most Expensive Semi-Precious Gemstone?

The most expensive semi-precious stone is alexandrite, as the price can reach up to dozens of thousand dollars/carat.

Because of the price, people in some countries consider alexandrite a precious stone. However, please, keep in mind that the precious/semi-precious classification is a bit outdated.

What is the Rarest Semi Precious Gemstone?

The rarest gemstones are poudretteite, paraiba tourmaline, taaffeite, tanzanite, laurentthomasite, red beryl, benitoite, alexandrite, musgravite, painite, grandidierite, jeremejevite, pezzottaite. According to the old precious/semi-precious gems classification, they are considered to be semi-precious.

Is Jade a Semi-Precious Gemstone?

Yes, according to the old classification, jade is a semi-precious gem.  However, the price for jadeite jade can reach up to million dollars, which is even bigger than that of precious gemstones. Gemologists suggest using the term gemstone, as precious/semi-precious is outdated now.

TIP: Jade is among the most beautiful gemstones in the world and you can find it in several states of the USA. Find out more in the article below:
Where to Find Jade: 4 Best Locations Near Me (United States)

What is the Difference Between Precious and Semi-precious Gemstones?

In ancient times, when advanced gemological equipment was not available, people used to separate gems into two groups only based on color mostly. They are precious and semi-precious. 

The main difference between precious and semi-precious gemstones is that there are only 4 precious stones that exist, according to this classification. They are diamond, ruby, emerald, and sapphire. All other gemstones are classified as semi-precious. Gem specialists consider this classification outdated. 

Gemologist and jewelry experts suggest using the term gemstone instead of precious or semi-precious, as some previously semi-precious stones can be rarer and far more expensive than precious stones.

Where to Buy Precious & Semi-precious Gemstones?

Precious and semi-precious stones, which are simply called gems now, are not hidden in luxurious boutiques but are widely distributed in shopping malls and online shops.

The biggest challenge the client faced is not to separate precious stones from semi-precious one. There are numerous high-quality simulants, imitations, and synthetic analogs, which are impossible to identify with the naked eye.

Buying precious and semi-precious stones is a very responsible activity, as there are a lot of stimulants available. A more important thing than the company or supplier you are buying from is a gemological certificate. Please, ask for a certificate each time while buying gemstones.


The main difference between precious and semi-precious stones is that precious stones are considered to be only four minerals, which are

  • diamond, 
  • ruby, 
  • sapphire, and 
  • emerald. 

Sometimes such gems as alexandrite, jade, pearl were added to the list. All other minerals, rocks, and organic materials belong to the semi-precious group.

However, gemologists and jewelry experts recommend avoiding using the terms precious and semi-precious as they are considered outdated and using the term gemstone for both previous groups. According to the World Jewelry Confederation and their CIBJO Blue Books, natural gemstones can be subdivided into two groups:

  1. Inorganic Gem Materials:
  • Minerals
  • Rocks
  • Natural glass 
  1. Organic/Biogenic materials
  • Plant origin 
  • Animal origin 

TIP: After reading this article, don’t feel like starting to collect gemstones? If you never do that, don’t worry, it is not so complicated. Check out the ultimate beginner guide about collecting rocks in the article below:
How to Start Rock Collecting? Complete Guide for Beginners