Home Ruby How to tell if Ruby Is real: A Comprehensive Guide

How to tell if Ruby Is real: A Comprehensive Guide

by Madonna

Ruby gemstones are prized for their captivating beauty and allure. As one of the most sought-after gemstones in the world, rubies hold significant value and are often subject to counterfeiting and misrepresentation. To ensure you are acquiring an authentic ruby gemstone, it is crucial to understand the key characteristics and identification methods used by gemologists and experts. In this article, we will delve into the various aspects that can help you determine if a ruby is real or not.

1. Understanding Rubies: Origins and Characteristics

Before delving into the identification process, it is crucial to understand the basic characteristics of rubies. Rubies are a variety of the mineral corundum, with their red color attributed to the presence of chromium. Natural rubies are formed deep within the Earth’s crust and are relatively rare and valuable. Synthetic rubies, on the other hand, are created in laboratories and have similar chemical compositions and physical properties to natural rubies.


2. Visual Assessment: Color, Clarity, and Cut

The visual assessment is the first step in determining if a ruby is real. Consider the following aspects:



A natural ruby typically exhibits a rich, vibrant red color. Look for a deep red hue with hints of pink or purplish undertones. Avoid rubies that appear too bright, orangey, or lack depth, as these may be signs of a synthetic or imitation stone.



Natural rubies often contain inclusions, which are internal flaws or tiny mineral crystals. These inclusions are usually visible under magnification and indicate the gemstone’s authenticity. Synthetic rubies, on the other hand, tend to have fewer inclusions or none at all. Be wary of rubies that appear flawless or too perfect, as they may be lab-created.


Pay attention to the cut of the ruby. Natural rubies are commonly faceted to enhance their brilliance and maximize light reflection. Look for well-proportioned cuts that exhibit symmetry and precision. Poorly cut or irregularly shaped stones may indicate an imitation.

3. Physical Properties: Hardness, Refractive Index, and Specific Gravity

Rubies possess unique physical properties that can aid in their identification:


Rubies are one of the hardest gemstones, scoring a 9 on the Mohs scale of mineral hardness. To test the hardness, rub the ruby against a known hard substance, such as a piece of quartz or a ceramic plate. If the ruby leaves a visible scratch on the surface, it is likely genuine.

Refractive Index:

The refractive index refers to how light bends when passing through a gemstone. Natural rubies have a refractive index between 1.76 and 1.78. To test the refractive index, place the ruby on a piece of white paper with printed text. If you can clearly read the text through the gemstone, it may not be a genuine ruby.

Specific Gravity:

The specific gravity of a gemstone is the ratio of its weight to the weight of an equal volume of water. The specific gravity of rubies ranges from 3.97 to 4.05. To test specific gravity, use a gemological balance to measure the weight of the ruby both in air and when submerged in water. Divide the weight in air by the loss of weight in water. If the result is close to the specific gravity range of rubies, it suggests the stone is genuine.

4. Examination under a Loupe or Microscope

A closer examination of the ruby under a loupe or microscope can reveal valuable information:


Inspect the ruby for natural inclusions, such as needle-like rutile or gas bubbles. These inclusions are typical in natural rubies but are less common in synthetic stones. Additionally, natural inclusions may exhibit characteristic features, such as the “silk” effect caused by intersecting needle-like inclusions.

Growth Lines:

Look for growth lines or “banding” within the ruby. Natural rubies often display these lines, indicating the crystal’s growth process. Synthetic rubies may lack these growth lines or display more regular patterns.

5. Conducting Advanced Tests: UV Fluorescence, Spectroscopy, and Raman Spectroscopy

For a more advanced assessment, several tests can help you evaluate the authenticity of a ruby:

UV Fluorescence:

Expose the ruby to long-wave and short-wave ultraviolet (UV) light sources. Natural rubies usually exhibit a weak to moderate red fluorescence under long-wave UV light, while synthetic rubies may show stronger fluorescence or different colors.


Spectroscopy techniques, such as infrared (IR) and visible spectrometry, can provide valuable information about the composition and molecular structure of a ruby. These tests require specialized equipment and expertise and are typically conducted by professionals.

Raman Spectroscopy:

Raman spectroscopy can analyze the vibrational modes of molecules and provide insights into a gemstone’s composition. This technique can help distinguish between natural and synthetic rubies, as their molecular structures may exhibit different patterns.

6. Seeking Professional Expertise

If you are still uncertain about the authenticity of a ruby, it is advisable to seek the expertise of a professional gemologist or a reputable jeweler. They have the knowledge, experience, and specialized tools to accurately assess gemstones. A professional evaluation can provide a definitive answer and offer peace of mind.

How much a ruby is worth

The value of a ruby can vary greatly depending on several factors, including its quality, size, color, clarity, and origin. Rubies are among the most valuable gemstones, and high-quality specimens can command significant prices.

To give you a general idea, smaller rubies of lower quality can be found for a few hundred dollars per carat. However, as the size and quality increase, so does the price. Fine rubies with exceptional color, clarity, and size can be valued in the thousands or even tens of thousands of dollars per carat.

It is important to note that the prices mentioned here are just rough estimates and can vary depending on market conditions, demand, and the expertise of the gemologist or jeweler.


Identifying a real ruby requires a combination of visual assessment, knowledge of physical properties, and the use of advanced tests. The color, clarity, cut, hardness, refractive index, and specific gravity are crucial factors to consider. However, it is important to note that some advanced tests, such as spectroscopy and Raman spectroscopy, require specialized equipment and expertise. If you are uncertain about the authenticity of a ruby, seeking the guidance of a qualified gemologist or jeweler is highly recommended. With the knowledge gained from this comprehensive guide and professional assistance, you can confidently determine if a ruby is real or not.

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