When choosing gemstone beads for jewelry making, I’d be willing to bet that color was one of the main considerations. Gemstones have been admired for their beauty and valued for their rarity for thousands of years. One of the most striking aspects of gemstones is their color, which can range from the bright red of ruby to the deep blue of sapphire to the iridescent play of color in an opal.
The color of a gemstone is determined by a variety of factors, including chemical composition, crystal structure, and external conditions. But in addition to their physical properties, many people believe that gemstones possess metaphysical properties, including the ability to enhance emotional, physical, and spiritual well-being. In this essay, we will explore what produces color in gemstones and the metaphysical properties associated with different colors.
Chemical Composition of Gemstone Beads
The chemical composition of a gemstone is the most important factor in determining its color. Many gemstone beads get their color from trace amounts of impurities in their crystal lattice. These impurities are known as chromophores and can be atoms or ions that replace some of the atoms in the crystal lattice.
For example, the red color of a ruby is caused by the presence of chromium atoms in the crystal lattice of corundum. Similarly, the green color of an emerald is caused by the presence of chromium and vanadium atoms in beryl.
The type and amount of impurities in a gemstone determine its color intensity, hue, and saturation. For example, a higher concentration of chromium in corundum produces a more intense red color in rubies.
On the other hand, a lower concentration of iron in beryl results in a lighter green color in emeralds. The same mineral can produce different colors depending on the type and amount of impurities present. For instance, corundum can produce red ruby beads or blue sapphires beads, depending on the presence or absence of chromium.
Crystal Structure of Gemstones
The crystal structure of a gemstone can also affect its color. The crystal structure determines how light interacts with the gemstone, and certain crystal structures can absorb or reflect different wavelengths of light, leading to different colors. For example, the blue color in sapphire beads is caused by the presence of titanium and iron in the crystal lattice, which absorbs all colors of light except blue. The crystal structure of a gemstone can also cause it to exhibit pleochroism, which means that the gemstone appears to have different colors when viewed from different angles. For example, a pleochroic gemstone like tanzanite can appear blue, violet, or brownish-yellow depending on the angle of observation.
External Factors that Affect Gemstone Color
Gemstone beads can also be affected by external conditions, such as heat, pressure, and radiation, which can alter their color. Pressure can also alter the color of some gemstone beads. For example, diamonds can turn brown or pink due to the extreme pressure and temperature conditions during their formation in the Earth’s mantle. Similarly, high-pressure treatment can turn a yellow diamond into a green diamond.
Human Treatments that Affect Gemstone Beads Color
The beautiful Natural Zircon beads shown here are the product of the natural forces that we’ve already discussed but many gemstones receive a treatment to alter or enhance the naturally occurring color.
Human factors can be used to produce or enhance color in gemstone beads include dyeing, irradiation, heat treatment, and coating. The use of these methods can alter the natural color of the gemstone or enhance it to create a more desirable color.
Dyeing Gemstone Beads
Dyeing is a common method used to alter the color of gemstone beads. Dyeing involves soaking the gemstone in a colored solution, which penetrates the stone and alters its natural color. Dyeing can be used to enhance the natural color of the gemstone or to create a completely new color. Dyeing is a relatively inexpensive method and can be done on almost any type of gemstone. However, the color produced by dyeing is not as durable as natural color and can fade over time, especially if exposed to sunlight or heat.
Commonly dyed gemstones are quartz, agate, and howlite. These gemstones are often dyed in bright colors, such as pink, blue, green, and purple, to create eye-catching jewelry designs. Some gemstones, such as freshwater pearls and mother of pearl, can also be dyed to create a wide range of colors, including black, gray, and brown.
Color Changes Produced by Irradiation
Irradiation is another method used to alter the color of gemstone beads. Irradiation involves exposing the gemstone to radiation, which can change its crystal structure and alter its color. Irradiation can be done using different types of radiation, such as gamma rays or electron beams. The color produced by irradiation depends on the type of gemstone and the radiation used. For example, irradiation can turn a colorless diamond into a green or blue diamond, or it can produce a variety of colors in topaz, including blue, green, pink, and yellow.
Irradiation can produce very intense and vibrant colors that are not found in nature. However, irradiated gemstones can also be less stable than natural gemstones and can fade or change color over time, especially if exposed to heat or sunlight. Therefore, irradiated gemstones must be treated with care to ensure their long-term color stability.
Heat Treating Gemstone Beads
Heat treatment is a method used to enhance the natural color of some gemstones or to create new colors. Heat treatment involves exposing the gemstone to high temperatures, which can change its crystal structure and alter its color. Heat treatment can also remove or reduce the appearance of inclusions or other imperfections in the gemstone.
The most commonly heat-treated gemstones are sapphires, rubies, and topaz. Heat treatment can turn a pale yellow topaz into a deep blue topaz, or it can enhance the color of a sapphire or ruby. The color produced by heat treatment is often more stable than the color produced by dyeing or irradiation. However, heat-treated gemstones can also be less valuable than natural gemstones, especially if the treatment is not disclosed. Here at Beadworks, we love all gemstones so while we may sell a treated stone, we also disclose that fact!
Coatings and Gemstone Beads
Coating is a relatively new method used to enhance the color and appearance of gemstone beads. It involves applying a thin layer of material, such as metal or synthetic material, to the surface of the gemstone to create a new color or enhance its natural color. Coating can also be used to give the gemstone a glossy or metallic finish, which can make it more appealing and valuable.
The coating material used depends on the desired effect and the type of gemstone. For example, metal coatings such as gold, silver, or copper can be applied to the surface of a gemstone to create a metallic finish. This can give the gemstone a more luxurious and expensive look, which can increase its value. Coatings can also be applied to gemstones to create a rainbow effect or an iridescent glow, which can be very striking and beautiful.
Synthetic materials can also be used for coating gemstones. For example, titanium oxide can be used to coat gemstones to create a wide range of colors, including blue, green, purple, and pink. This method is often used to enhance the natural color of gemstones, such as pearls or quartz, and create a unique and attractive appearance. Synthetic materials can also be used to create a glitter effect on the surface of the gemstone, which can add sparkle and shine.
Coating is a relatively inexpensive method compared to other methods of enhancing the color and appearance of gemstones. However, coated gemstones are not as durable as natural gemstones, and the coating can wear off over time, especially if exposed to heat, sunlight, or chemicals. Therefore, it is important to take care of coated gemstones and avoid exposing them to harsh conditions.