Natural vs Synthetic Gemstones: How to Understand the Difference

Quick Answer

Natural gemstones form over millions of years inside the earth through natural geological processes, while synthetic gemstones recreate the same chemical and physical composition in a laboratory within a few weeks or months. The two can have almost identical structure, but there’s a world of difference in rarity and price. Only a lab certificate can reliably tell you which gemstone you actually have.

Introduction

The first and most basic question when buying a gemstone should be — is this gemstone natural or synthetic? This question is a bit different from identifying genuine versus fake (covered in detail in our How to Identify a Genuine Gemstone guide), because a synthetic gemstone isn’t actually “fake” — it’s a legitimate product in its own right, provided it’s honestly sold as synthetic. The problem arises when a synthetic gemstone is sold as natural, at natural-gemstone prices. In this article, we’ll understand the technical difference between the two, how synthetic gemstones are made, and what you should keep in mind as a buyer.

How Natural Gemstones Form

Natural gemstones form beneath the earth’s surface, under conditions of extreme pressure and temperature, through a geological process spanning millions of years. During this long process, surrounding minerals, gas bubbles, and other elements leave tiny marks inside the gemstone — called inclusions. These natural inclusions and their irregular growth pattern are considered the biggest proof of a gemstone’s natural origin, since they’re extremely difficult to fully replicate in a laboratory. This is why natural gemstones are available in limited quantities and their price remains comparatively high.

How Synthetic Gemstones Are Made

Synthetic gemstones are made in a laboratory using the same chemical elements that form a natural gemstone, so their optical and chemical properties closely resemble those of a natural gemstone. Some of the main methods used to make them are:

• Flame-Fusion / Verneuil Process: This is the oldest method, developed in 1902. Fine powder is melted in an intense flame and gradually deposited into crystal form. It remains the most common and cheapest method for making synthetic ruby and sapphire today.
• Flux-Growth: Here, the chemical elements that form the gemstone are dissolved in a molten “flux” medium and gradually cooled to grow into crystal form. This process is slower than flame-fusion, and the crystals it produces can show inclusions more similar to natural gemstones.
• Hydrothermal Growth: Here, the gemstone is gradually grown in a water-like solution under high temperature and pressure — a process somewhat similar to how natural gemstones form, just compressed into far less time.

In all of these methods, the gemstone is ready in a few weeks to a few months, whereas a natural gemstone takes millions of years to form.

How to Tell the Two Apart

For an average buyer, telling a synthetic gemstone apart from a natural one with the naked eye is nearly impossible, since both can have identical colour, shine, and hardness. Only a recognized gemological lab can reliably determine whether a gemstone is natural or synthetic, by examining its inclusions and growth pattern under a microscope, and in some cases using advanced tools like trace-element analysis. So before any valuable purchase, the certificate should clearly state whether the gemstone is “Natural” or “Synthetic” — this is explained in detail in our Understanding Your Gemstone Report guide.

Traditional Belief and Synthetic Gemstones

According to traditional belief, in the tradition of wearing gemstones for astrological purposes, only a natural gemstone is considered valid — a synthetic gemstone isn’t considered suitable for this purpose. This belief is rooted in faith and tradition, not scientific fact. So if you want to wear a gemstone based on astrological advice, specifically ask the seller for a natural gemstone and make sure to check this is confirmed on the certificate. On the other hand, if your purpose is purely aesthetic or for a collection, an honestly sold synthetic gemstone can also be a reasonable and affordable option.

Quick Facts

Point	Natural Gemstone	Synthetic Gemstone
Where it forms	Inside the earth	Laboratory
Time to form	Millions of years	A few weeks to months
Chemical/optical properties	Original	Nearly identical
Price	Comparatively high	A fraction of the natural gemstone’s price
Identifiable at home?	No	No
Traditional astrological validity	Valid	Considered invalid by tradition

Expert Tip: Don’t trust any gemstone just because it’s called “genuine” — the certificate should clearly say “Natural” in plain words, not “Synthetic” or “Lab-Created.” This one-word difference can mean a many-fold difference in price.

Buying Advice

Since telling natural and synthetic gemstones apart isn’t possible without a lab certificate, always buy from a certified seller and, if possible, compare quotations from different sellers so you can verify both price and certificate — get in touch with us for help with this.

Key Takeaways

• A synthetic gemstone isn’t fake — it’s a separate, legitimate product category, provided it’s honestly disclosed.
• Flame-fusion, flux-growth, and hydrothermal growth are the three main methods used to make synthetic gemstones.
• It’s not possible to tell natural and synthetic apart with the naked eye or home tests.
• Only a recognized lab certificate can give a reliable answer.
• According to traditional belief, only a natural gemstone is considered suitable for astrological purposes.

Conclusion

Understanding the difference between natural and synthetic gemstones is a buyer’s most basic responsibility. Both are legitimate products in their own right, but getting the right one matters for price and purpose — and that confirmation can only come from a trustworthy lab certificate.