Which Gemstone Should I Buy?

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The other day, a customer asked me, “which gemstone is suitable for me and which one should I buy?” 

There are so many types of gemstones you can buy. You may get overwhelmed with the options.

With a few criteria that help you narrow down the choices, this article will help you find the perfect gemstone.


Gemstones come in all colors. Basically in any color you can think of. So if you have a color in mind, you can pretty much find something that matches. 

Here are some common colors and selected gemstones:


  • Ruby
  • Rubellite (red tourmaline)
  • Garnet
  • Strawberry Quartz


  • Kunzite
  • Rose quartz
  • Pink Opal
  • Rhodochrosite


  • Carnelian
  • Morganite
  • Orange garnet
  • Sunstone


  • Citrine
  • Topaz
  • Amber
  • Gold Rutilated Quartz


  • Emerald
  • Peridot
  • Tsavorite garnet
  • Bloodstone


  • Sapphire
  • Aquamarine
  • Tanzanite
  • Turquoise


  • Amethyst
  • Charoite
  • Phosphosiderite

White or Colorless

  • Diamond
  • Moonstone
  • Quartz


  • Smoky quartz
  • Brown tourmaline
  • Tiger’s Eye


  • Onyx
  • Schorl (Black Tourmaline)
  • Obsidian

And there are many gemstones that have more than one color, like tourmaline, sapphire, zircon, spinel, fluorite, etc.

Also there are some gemstones that are hard to categorize into a color, for example, opal with its shimmering colors, and labradorite with its colorful reflection.

Different cuts of gemstone

Faceted gemstones have different cuts available. Here are some common ones you can find in the market:







Emerald cut blue topaz

The look and optical properties of gemstones

Gemstones have many different looks. You probably know some, like the blue sheen of moonstone, and the band of light of a ‘cat’s eye’ gem.

Here is an introduction to some optical properties and effects of gemstones:

Maharani Cat's Eye Chrysoberyl. Photo from Smithsonian National Museum of Natural History

Chatoyance and cat’s eye

Caused by: Very small parallel inclusion inside the gem, and the light reflects in a concentrated band of light

Gemstones with this effect: Cat’s Eye chrysoberyl, tiger’s eye, etc.


The Delong star ruby. Photo from Reddit

Asterism (star effect)

Caused by: Similar to cat’s eye effect, but with more parallel inclusions in different directions. The star can be 4-ray, 6-ray and 12-ray, with 6-ray being the most well known

Gemstones with this effect: star ruby, star sapphire, star rose quartz, etc.


Opal with play of color

Play of color

Caused by: Many tiny silica spheres inside the opal that acts like prisms. When light enters, they get broken into different colors. The result is shimmering color play

Gemstones with this effect: Opal


Moonstone with adularescence


Caused by: When light is entered and reflected between two or multiple layers of minerals. The layers are very close to each other. The result is a glow or reflection that seems to float on the surface of the gem

Gemstones with this effect: Moonstone


Whitney Alexandrite. Photo from Smithsonian National Museum of Natural History

Color change

Caused by: Different light sources have different wavelengths. Color change gemstones are able to absorb different colors of light in different light source

Gemstones with this effect: Alexandrite, color change garnet, etc.


Ammolite with 3 iridescence colors. Photo from Unearthed Gemstones

Iridescence (including adularescence of moonstone and labradorescence of labradorite)

Caused by: When light is entered and reflected between two or multiple close layers of minerals. The light gets broken down into different colors in some cases. This produces a glow or shine of the gemstone.

Gemstones with this effect: Moonstone, ammolite, labradorite etc.

Price and affordability

Different gemstones vary greatly in values. A perfect 1 carat diamond ring can cost as much as US$20,000, and an amethyst ring can be bought with less than $100. 

You probably have a price range in mind of how much you want to spend. Here are the main factors affecting the value of gemstone:


The rarer the gemstone is, the higher the price it will be. A ruby, which is a rare gemstone, will almost always be more expensive than an agate, which is much more common. 

Agate is a relatively common gemstone


As you may know, the better quality gemstone will be more expensive. It can be richer color and higher clarity. A vivid blue aquamarine with no flaws will demand a higher price than an opaque light blue one.


The more saturated the color, the higher the gem’s value. Some colors are more valuable, like a blue tourmaline is more valuable than a brown one. Both because of market demand and rarity. Grey, brown, black are usually cheaper color options.


The bigger the gem, the more expensive it is. This is especially true for rarer gemstones. A big ruby can cost exponentially more than a smaller one. For example, doubling the size may triple or even quadruple the price.

A blue tourmaline is usually more expensive than colors like brown. Photo from King Stone Gems

This is just an overview of the factors affecting the price of a gemstone. There are a few other ones like gemstone treatment, cut, market trend, etc, that change the price of the gemstone.


Here is a price chart for some gemstones (given that their quality is comparable): 


  • Diamond
  • Ruby
  • Sapphire 
  • Emerald


  • Aquamarine
  • Tourmaline 
  • Garnet
  • Tanzanite
  • Peridot
  • Kunzite
  • Moonstone


  • Quartz like amethyst and citrine
  • Agate
  • Jasper
  • Obsidian


Some gems are easier to get damaged than others. For example, nephrite jade and jadeite jade are two of the most durable gemstones, while gemstones like emerald and topaz are much more prone to breakage. 

If you want to wear less durable or softer stones, try looking for jewelry with protective settings. 

You can read this topic more in depth in this article about durability of gemstones.

Natural or treated gemstone

You can also consider whether the gemstone is treated. Most people would prefer a natural untreated gemstone over a treated one. 

In general, an untreated gemstone will be more expensive. For example, an untreated high quality ruby will claim 3-5x the times of a treated one.

However, some sellers don’t fully disclose the treatment that a gem went through. Also, some misuse the word natural to mean genuine. 

Heat treatment is one of the more common treatments of gemstone. It’s usually used to enhance the color of gemstones. However, sometimes it’s not detectable even the seller claims the gem is unheated.

Healing properties

Many people buy gemstones based on their healing properties. For example, citrine for money and rose quartz for love. As I’m not an expert on this aspect, I encourage you to do the research and find out which gemstone feels the best to you 🙂

With the help of these guidelines, you can now narrow down and pick your perfect gemstone.

If you are still unsure, feel free to browse Unearthed Gemstones to see if there is any that catches your eyes. New gems are constantly being added.