Understanding Different Types of Gemstones

Elegance does not necessarily have to come from the classic route.

Some of the most memorable pieces of jewelry are because of some individual who decided to do things differently by rotating the diamond, using two diamonds instead of one, playing around with negative space, or simply choosing a unique shape.

Diamond jewelry grown in a laboratory opens up the opportunity to play around with different styles such as the toi et moi ring, kite diamonds, and even suspended diamonds. All this can be achieved without breaking the bank compared to the natural diamond counterpart.

Unique doesn’t necessarily mean complicated.

The Gemstone Classification System: From Where Everything Starts

 Precious vs. Semi-Precious

For the longest time, the classification system for gemstones consisted of precious and semi-precious types.

The four traditionally accepted precious gemstones were:

Diamond (including lab-created diamond)
Ruby
Emerald
Sapphire

All others were considered to be semi-precious. However, such terms do not indicate either the value or rarity of the stone in question. In reality, the rarest type of alexandrite can be worth more and more valuable than an ordinary type of ruby.

Therefore, one can say that the term precious vs. semi-precious is a mere **industry tradition**, nothing else.

 Natural vs. Lab-Created vs. Simulant

Here is what makes the sense to the modern buyer of jewelry:

Natural gems: Are formed in the course of millions or even billions of years and mined from the Earth's crust.

Lab-created gemstones: Created by man in the lab. These gemstones have exactly the same chemical composition and properties of those which are formed naturally. Lab-created diamonds, sapphires, rubies and emeralds belong here.

Simulants: Are created only in imitation of another kind of gemstone. For example, cubic zirconium (or just CZ) is a stone that mimics diamond, though it has nothing to do with diamond.

The key to understanding lies in the following statement: lab-created diamonds are diamonds, CZ is a diamond simulant.

The Mohs Hardness Scale: The Most Important Number in Gemology

There is a single number every jewelry buyer needs to know before selecting the stone: Mohs hardness.

The Mohs hardness scale defines a resistance of a mineral to scratching from other minerals. Ranging from 1 (talc) to 10 (diamond), Mohs hardness is particularly important to jewelry since harder minerals will scratch softer ones.

Since daily wear jewelry comes into contact with various materials including dust, its hardness becomes an important criterion. Quartz – the common constituent of dust – has a Mohs hardness of 7. That means stones with hardness below 7 will be exposed to risk of scratches when used daily.

 Comparison of Common Gemstones by Mohs Hardness

Diamond – 10: Great choice for daily use and the hardest mineral in the world.
Ruby and Sapphire – 9: Great options for daily rings and bracelets.
Alexandrite – 8.5: Highly resistant to scratches and durable.
Topaz – 8: Durable enough, however, reasonable care is required.
Emerald – 7.5–8: Satisfactory hardness, although natural inclusions reduce its resistance.
Aquamarine – 7.5–8: Good for daily jewelry if proper care is exercised.
Amethyst – 7: Satisfactory hardness; however, more exposed to scratches compared to harder stones.
Tourmaline – 7–7.5: Can be used daily with reasonable care.
Garnet – 6.5–7.5: Depending on type of garnet, its hardness can vary.
Opal – 5.5–6.5: Quite delicate material, not good for rings.
Pearl – 2.5–4.5: Very soft and fragile material.

For rings and bracelets, stones that have Mohs hardness of 8 and above are preferable since such jewelry is subject to more contact.

Gemstones with hardness below 7 are better for making earrings and necklaces since they are less likely to get into contact with rough surfaces. Even so, softer stones are great choice, only they need more care.

The Precious Four: A Deep Dive

 Diamonds — Lab Grown & Natural

What they are: Diamonds consist of pure carbon in the form of a crystal structure. They have the highest Mohs scale hardness rating of 10 and thus are the hardest mineral.

Difference between lab grown and natural: Lab grown and natural diamonds are made of the same elements and have the same crystal structure. Both types of diamonds are classified by organizations like GIA and IGI and evaluated on the basis of 4C parameters. Their only difference is the way in which they formed and the price.

What makes them unique: Due to their unique hardness and optical qualities, diamonds make excellent jewelry that one can wear daily.

Best used for: Engagement rings, wedding bands, earrings, necklaces and other pieces of everyday jewelry.

Color grades: There are standard color ratings of diamonds, from D to Z. From there, fancy colored diamonds are available in different colors such as blue, pink, yellow, green, and orange.

Popular diamond shapes: There are many popular shapes of diamonds such as round brilliant, oval, cushion, pear, emerald, princess, marquise, radiant, and Asscher.

Rubies - The Red Gemstone with an Equivalent Hardness

What are they? Rubies are the red corundum varieties which are mostly made of aluminum oxide. Chromium is the element which causes the color red in the gemstones. With the hardness of 9 on the Mohs scale, they rank second among the most durable gemstones for daily jewelry.

What should you know? Among the parameters affecting the quality of rubies, color stands out the most. The most valuable rubies have a very pure and bright red color, also known as "pigeon's blood". Natural inclusions are typical and accepted in the gemstone.

Heat treatment: Heat treatment is applied to most rubies for color and clarity improvement. Untreated rubies of high quality can be much more expensive, and, therefore, the treatment disclosure by reputable dealers is mandatory.

Lab-grown rubies: The lab-grown rubies contain almost the same composition and crystal structure as natural rubies. This type offers an opportunity to own a classic red gemstone at a reasonable price.

Suitable for: As rubies are highly durable and colored brightly, they are great choices for engagement rings, daily rings, pendants, and other pieces of frequently-worn jewelry.

What to look for? The color should be vivid and even; the transparency and treatment should be disclosed. Do not opt for the stones with a brownish, purplish, or opaque appearance, and many inclusions, if such look is not intentional.

Sapphires - Not Just Blue

About: Sapphires are corundum gemstones, with a Mohs hardness of 9. If it is red in color, it is called ruby, otherwise, it is sapphire. Blue color is the best-known, however, there are many other colors, including pink, yellow, purple, green, orange, and the very rare padparadscha pink-orange color.

Blue sapphire: Classic color variety with colors from light blue to royal blue shades. Best-quality blue sapphires are known to come from Kashmir, Myanmar, and Sri Lanka. Heat treatments are frequent and should always be declared.

Pink sapphire: Another color variety that can be used in engagement rings and fashionable jewelry. Romantic pink color offers a great alternative to the traditional blue.

Yellow sapphire: Color alternative to yellow diamonds and usually less expensive than diamonds. Good hardness makes this gemstone perfect for everyday use.

White sapphires: Often used as a diamond alternative, however, white sapphires have less brilliance than diamonds and are somewhat softer. Can be used as accent stones in jewelry designs.

Lab-created sapphires: Lab-created sapphires have all the chemical and physical characteristics of natural sapphires and are frequently used in jewelry. Modern designs with lab-grown diamond accents and sapphires are also popular.

For what? Sapphires can be used in rings, earrings, pendants, necklaces, and other jewelry pieces. Being one of the hardest colored gems, Mohs 9 hardness makes sapphires ideal gemstones for everyday jewelry.

 Emeralds - The Green Gemstone That Needs Special Care

What they are: Emeralds are a green form of beryl with a Mohs hardness of 7.5 – 8. The presence of chromium and vanadium gives the stone its typical green color. Colombia, Zambia, and Brazil are the most famous sources.

What sets emeralds apart: Unlike most gemstones, almost all emeralds will have some type of internal inclusions which are known as jardin or "garden" in French. Inclusions are the inherent feature of an emerald and because many stones are heavily included, high-quality clear untreated emeralds will be very rare and expensive.

Treatments: Most emeralds are treated with oils and other substances to enhance surface-reaches fractures. While this practice is widespread in the gem trade, it is still important to know what treatment the emerald has received.

Durability note: Even though the emerald is fairly hard, its inherent inclusions make it more prone to chipping and breaking than rubies and sapphires. More care should be taken with this stone, especially when wearing emerald rings or bracelets.

Best for: Emeralds are best used in earrings, necklaces, and pendants. Emerald rings can also make beautiful jewelry if you do not mind taking additional precautions when wearing them unlike diamond, ruby, or sapphire rings.

Lab grown emeralds: Lab grown emeralds are also available on the market and generally have less inclusions compared to most natural emeralds which makes them look clearer.

The Semi-Precious Category: A Richer World Than the Name Suggests

Being semi-precious does not make a gemstone any less precious. The term is used only to differentiate between those gemstones that do not belong to the "precious four" and that have their individual color, hardness, and requirements for proper care.

Amethyst – Purple Quartz With Numerous Possibilities

What it is: Amethyst is a purple-colored form of quartz, which has the Mohs hardness of 7. The colors vary from light lavender to deep violet.

Practical considerations: Amethyst is a perfect stone for wearing in earrings and pendants. The stone is also possible to wear in rings, however, since it is rather soft for daily use, caution is advised.

Good for: February Birthstones, Purple Gemstone Jewelry, Earrings, Necklaces; amethyst can be combined with lab diamonds in jewelry.

Aquamarine – Blue-Green Color That Will Not Disappoint You

What it is: Aquamarine is a blue or blue-green variety of beryl, just like emeralds. Its Mohs hardness is 7.5 to 8.

Practical considerations: Having great hardness and clean appearance, aquamarine belongs to the most practical colored gemstones.

Good for: March Birthstone Jewelry, Rings, Earrings, Pendants; aquamarine looks great combined with lab diamonds.

Garnet – Not Just Red

What it is: Garnet is a family of minerals with a hardness varying from 6.5–7.5. Its color varies from red to green, orange, pink and more.

What you should know: Red garnet is not ruby. These two gems are totally different. There are also varieties that serve as good alternatives to red garnet – for example, tsavorite, demantoid, spessartine, and rhodolite.

Best for: January birthstone jewelry, colorful rings and pendants. Harder garnets are preferable for rings that will be worn every day.

Opal – Play-of-Color Wonder, Fragile Gemstone

What it is: Opal is an amorphous form of silica that displays unique play-of-color effect that can produce various colors when gemstone changes its position.

The durability truth: Being a fragile gemstone, opal has a Mohs hardness of 5.5-6.5 and can be susceptible to temperature changes.

Best for: Earrings and pendants. Opal is not suitable for wearing in rings every day.

Pearls – Organics in Gemworld

What they are: Pearls are organics made by mollusks. They consist of nacre layers covering an irritant. Pearls are not mineral gemstones.

Types: Popular varieties are natural pearls, cultured pearls, freshwater pearls, Akoya pearls, Tahitian pearls, and South Sea pearls. Cultured pearls compose a majority of pearls used in jewelry today.

Durability: Pearls are very soft (their Mohs hardness is 2.5-4.5). They scratch easily and may be sensitive to perfumes, cosmetics, acids and perspiration.

Best for: Earrings and pendants, especially for special occasions.

Choosing a Suitable Gemstone for Your Jewelry

Deciding on a gemstone is a lot easier when considering how you will wear the jewelry.

 Everyday Wear Rings & Bracelets

Perfect choice: Diamonds whether they are lab-made or natural and their Mohs hardness rating is 10. These gems provide great scratch resistance and are suitable for wearing every day.

Great alternatives: Ruby and sapphire gems. Their Mohs hardness is 9 and both these gems are durable enough to use for everyday rings and bracelets.

Acceptable with some care: Alexandrite, topaz, and aquamarine. All three gems are durable enough for everyday jewelry; however, they do need some care.

More cautious: Emerald, amethyst, and some garnets should be worn with extra care. The fact is that emeralds have inclusions, amethyst and some garnets have a lower hardness rating.

It's better not to use for rings worn every day: Opal and pearl gems. Both gems have low hardness and will scratch easier than other gems.

 Pendants & Earrings

Pendants and earrings usually receive much less physical impact so you can pick whatever gemstone you like.

Suitable choices for pendants and earrings: Opal, pearl, amethyst, garnet, emerald, aquamarine, sapphire, ruby, and diamond. These gems look fantastic if properly set.

This is the situation when color, personality, and design are more important than hardness.

 For Jewelry that Will Be Passed on Generations

In case you are buying jewelry that you want to give to next generations consider durability and rarity.

Natural diamonds, fine natural rubies, and sapphires along with high-quality untreated colored gemstones have great collecting value. In addition, certification of the origin, treatments and quality of the gemstone add value to your jewelry.

Lab-grown diamonds and lab-grown colored gemstones are great in their beauty and value, but they lack rareness and therefore are not considered as collector's items.

Easy rule: Harder gemstones for wearing daily and soft gemstones in case you focus on beauty of the piece.

Lab-Grown Diamonds in Gemstone Selection

Among the current choice of gemstones, lab-grown diamonds present one of the most durable, brilliant and valuable choices for jewelry shoppers.

Mohs hardness rating of 10: Lab-grown diamonds are extremely resistant to scratching; thus, suitable for daily wear.
Identical chemistry to that of natural diamonds: Lab-grown diamonds have identical chemical structure and crystal formation properties as natural diamonds.
Affordable: Lab-grown diamonds tend to be substantially less expensive than their natural counterparts.
Certification from independent sources: Lab-grown diamonds may be evaluated by third-party evaluators, such as GIA and IGI, applying standard diamond grading guidelines.
Do not require mining: Lab-grown diamonds are produced in laboratory setting as opposed to natural diamonds that are extracted by means of diamond mining.

In case of buyers in need of durable and brilliant gemstone for fine jewelry, engagement rings , wedding rings and stud earrings lab-grown diamonds provide a decent selection among the other alternatives.

Should you be interested in additional coloration, lab-grown diamond accents together with gemstones such as sapphire, ruby, emerald and amethyst would produce a wonderful contrast.

Common Gemstone Buying Mistakes

Picking a gemstone just because it looks good. That pretty opal ring might seem like an excellent choice, but it is relatively fragile and can be scratched or cracked rather easily. Make sure you take into account the hardness of the stone before purchasing a ring.

Thinking all rubies and sapphires have the same type of treatment. Heat treatment is common for them, but types of treatment could be different. Some heavily fractured rubies are also filled with glass, so always inquire about the kind of treatment done.

Confusing synthetic gemstones with simulants. Topaz is not diamond, and cubic zirconia is not diamond either. Lab-created diamonds are diamonds, but simulants are not diamonds; they only have a similar appearance to diamonds.

Buying expensive colored gemstones without any certificate. Consider getting a report from the independent laboratory for your valuable gems. It will contain information about the stone's identity, treatment, and all other relevant features. It is helpful especially when buying expensive rubies, sapphires, emeralds, and rare colored gemstones.

Not taking care of maintenance needs. Every gemstone should be cleaned differently. Both diamonds and many sapphires can withstand ultrasonic cleaning; however, opals and pearls need a more careful approach. Emeralds might need additional maintenance depending on their treatment and inclusion content.

General rule: do not base your choice on beauty alone. Think of the hardness, treatment, maintenance needs, and certification before picking a gemstone.

Frequently Asked Questions

Q1: What is the difference between precious and semi-precious gemstones?

Precious gemstones traditionally include diamonds, rubies, sapphires, and emeralds, while semi-precious gemstones include amethyst, garnet, aquamarine, and topaz.

Q2: Are lab-grown diamonds considered real gemstones?

Yes, lab-grown diamonds are real gemstones.

Q3: What is the hardest gemstone?

Q4: Which gemstone is best for an engagement ring?

Q5: What's the difference between lab-grown diamonds and cubic zirconia?