Diamonds and Gemstones: What’s the Difference?

When people think of fine jewelry, diamonds often come to mind. But the world of gemstones is far broader and more colorful than just the classic beautiful diamond. So what exactly sets diamonds apart from other gemstones? This blog will explore the key difference in formation, classification, grading, and pricing between diamonds and colored gemstones.

What Are Diamonds and Gemstones?

Diamonds are a specific type of gemstone composed of carbon atoms arranged in a crystal lattice. They are prized for their brilliance and hardness (the hardest natural material on Earth, and are rated 10 on the MOHs scale). Diamonds have industrial uses as well as being popular for use in engagement rings and luxury jewelry. Shown are a diamond engagement ring, a diamond tennis bracelet, and a diamond wedding ring set.

Gemstones is a broader category that includes any mineral (and some organic materials like amber and pearl) that is cut and polished for use in jewelry. This includes diamonds, but also colored gemstones like emeralds, rubies, sapphires (both rubies and sapphires are a variety of corundum and rate 9 on the MOHS scale), as well as many others. Featured are emerald earrings, a ruby & diamond ring, and a sapphire & diamond halo bracelet.

How Are They Formed?

Diamonds form deep within the earth’s mantle under extreme pressure and heat over a prolonged period of time. They are brought to the earth’s surface through volcanic eruptions in rocks called kimberlites. 

Gemstones form in a variety of geological environments and are cut and polished for use in jewelry or decoration. Some, like emeralds, beryl, and tourmaline crystallize in hydrothermal veins. Featured are an emerald & diamond eternity band, a green beryl & diamond necklace, and salmon tourmaline & diamond earrings,

Zircon, peridot, and topaz are formed from magma or lava. Below are a white gold zircon with diamond halo ring, peridot earrings, and a blue topaz diamond pendant.

Garnets, sapphires, rubies, and spinel form under high-pressure metamorphic conditions. Their host rocks vary and include igneous, metamorphic, and sedimentary types. Shown are a garnet & diamond ring, a Madagascar no-heat purple sapphire & diamond ring, and a red spinel & diamond ring. 

Opal, malachite, turquoise, and azurite form when minerals dissolve in water, settle, and gradually form crystals, or existing gemstones erode and get deposited in riverbed or sediment layers. Pictured are an opal & diamond marquise style ring, a vintage malachite, and turquoise ring, 

Amber, pearl, and coral form from biological processes, like the shells or secretions of living organisms. Below are an amber pendant, a baroque pearl & diamond hinged cuff, and a coral & diamond necklace.

  

Precious vs. Semi-Precious Stones

Historically, gemstones were divided into precious and semi-precious categories. Precious gemstones include diamond, ruby, sapphire, and emerald. All other gemstones were labeled semi-precious. 

Today, gemologists discourage this terminology because many so-called “semi-precious” stones like alexandrite or paraiba tourmaline can be rarer and more valuable than some precious gemstones. Modern valuation is based more on quality, rarity, and market demand rather than outdated categories. 

Here are some examples of “semi-precious” gemstones with an alexandrite eternity band and a paraiba cuprian tourmaline and diamond ring.

Below, more “semi-precious” gemstones are an amethyst ring, an aquamarine ring, an opal pendant, and a turquoise & diamond necklace.

Grading Systems: Diamond vs. Gemstones

The Gemological Institute of America (GIA) created diamond grading to determine gem-quality by using the standardized 4Cs of :

• Color (D to Z for white diamonds), 

• Clarity examines inclusions and impurities of the gemstone (FL to I3),

• Diamond cut (excellent to poor), 

• Carat weight (not to be confused with diamond shape)

Buying a beautiful diamond means more than looking at a single element of the 4Cs. The diamond cut is important for the best light dispersion and sparkle of your diamond gemstone. The cut quality highlights the gemstone’s proportions, symmetry, and polish. The clarity, color and carat weight also play into a diamond’s value.

Colored Diamonds have their own unique system. Color grading uses terms like Fancy Light, Fancy Intense, and Fancy Vivid. Clarity and cut are still evaluated but color dominates value. Australia has many diamond mines that are known for their colored diamonds. Shown is a fancy intense yellow diamond and a black diamond necklace.

Colored Gemstones are graded differently, usually with the following factors.

• Color is evaluated by hue (basic color), tone (lightness or darkness), and saturation (vivid, strong, dull). 

• Clarity is more lenient and varies by the actual gemstone type. 

• Cut is judged for craftsmanship and how well it enhances the stone's color. 

• Carat weight is the standard weight measurement. 

• Treatment disclosure tells whether the gemstone has been heated, irradiated, dyed, etc. (untreated typically command higher prices)

• Origin is sometimes included and can significantly impact their value.

What Determines the Price?

Diamonds are priced primarily based on the 4Cs, with the high emphasis on cut and clarity in colorless diamonds. Market demand, especially for engagement rings, also plays a role.

Colored diamonds like the Hope Blue Diamond from South Africa and the Pink Diamond from Australia are examples of natural diamonds that are rare, have exceptional quality, and high market demand.

Gemstones are priced based on color quality (vividness and purity), size, clarity, and whether they are treated or untreated. Rarity and origin can significantly affect price, For example, paraiba tourmaline is extremely rare and is neon blue-green in color. Alexandrite is color-changing and very rare. Colombian emeralds are sought after due to their high quality. A vivid, untreated Burmese ruby can be worth far more than a high-quality diamond.

Below is a paraiba tourmaline ring, a Columbian emerald ring, and a Burmese ruby & pave diamond ring.

Lab-grown diamonds (synthetic diamonds) and lab-grown gemstones, or treated versions of gemstones are common, and are much cheaper than the natural versions. Below are a lab-grown sapphire & white topaz ring, an irradiated blue diamond band, and an irradiated blue diamond engagement ring, 

Lab certificates from GIA, AGL,IGI, etc. for diamonds and gemstones authenticate quality, treatment, and the origin of natural diamonds and gemstones. Certified gemstones are more trusted, and will command higher prices. 

Conclusion

Diamonds are just one chapter in the colorful book of gemstones. While they are prized for their durability and brilliance, other gemstones offer a wide range of hues, histories, and unique value. 

Whether you’re buying a birthstone, an anniversary present, diamond jewelry, or collecting gems, understanding the differences in formation, classification, grading, and pricing can help you make informed and meaningful choices.

By exploring beyond the diamond, you might just find a gemstone that speaks more personally to your style and story. The Estate Watch and Jewelry Company has a large selection of both diamonds and colored gemstones that you will be sure to love. Look us up online or stop in and see us. We would love to help you find your desired gemstone!