Gemstones are naturally beautiful, but humans have always enhanced their appearance through various treatments, and occasionally even created synthetic or simulated alternatives. Here's a straightforward guide to help you understand the basics of gemstone treatments, simulants, composites, and synthetics.
Gemstone Treatments
What are gemstone treatments?
Gemstone treatments are processes used to improve the appearance, durability, or value of natural gemstones. Common treatments include heating, irradiation, impregnation, coating, dyeing, and bleaching.
Why do we treat gemstones?
We treat gemstones to enhance their colour, clarity, and durability, making them more appealing and marketable. For instance, heating sapphires can intensify their blue colour and remove unwanted hues.
Are treatments detectable with tests?
Many treatments are detectable by standard gemmological testing but some required advanced lab testing:
- Heating: Often detectable with microscopy by identifying altered internal features such as melted inclusions or stress fractures. Heating can also be identified by changes in pleochroism when examined with a dichroscope.
- Irradiation: Detectable through advanced spectroscopy, as irradiation often alters colour in distinctive ways. Sometimes the colour created does not exist naturally in nature so a deduction that some materials are heated can be made.
- Dyeing: Usually detected through magnification, revealing dye concentrations along cracks.
- Coating: Easily detectable with magnification.
- Bleaching and impregnation: Detected under magnification and specific tests for fillers.
How likely are gemstone treatments used?
Treatments are extremely common. For example, most sapphires and rubies sold commercially have undergone heat treatment. Disclosure of treatments is standard practice in reputable gem markets.
Gemstone Simulants
What are simulants?
Simulants are materials that resemble gemstones but have completely different chemical compositions. For example, cubic zirconia is commonly used as a diamond simulant.
Why do we use simulants?
Simulants offer an affordable alternative, allowing consumers to enjoy the look of expensive gemstones without the high cost.
Are simulants detectable with tests?
Yes. Gemmological tests like refractive index, hardness tests, and microscopy easily distinguish simulants from the gemstones they are imitating.
How likely are simulants used?
Simulants are very common, particularly in jewellery markets catering to affordability, fashion, or costume jewellery.
Gemstone Composites
What are composites?
Composite gemstones are created by bonding two or more materials. For instance, opal doublets and triplets are composites where a thin slice of opal is bonded to a supportive base.
Why do we create composites?
Composites help improve durability, reduce costs, and allow the use of fragile or thin gemstone slices.
Are composites detectable with tests?
Yes, composites are generally easy to detect through magnification, revealing bonding lines, glue layers, or differences in material layers.
How likely are composites used?
Composites are fairly common, especially in fragile materials like opal and turquoise.
Synthetic Gemstones
What are synthetic gemstones?
Synthetic gemstones have the exact chemical and physical properties as natural gems but are grown artificially in a lab.
Why do we create synthetics?
Synthetics offer gemstones at a lower price and higher availability, ensuring consistent quality and supply.
Are synthetics detectable with tests?
Most synthetics can be detected through microscopy or advanced spectroscopy, which reveal growth patterns unique to laboratory conditions.
How likely are synthetic gemstones used?
Synthetic gemstones are widely used in various jewellery sectors due to their affordability and consistency, especially for gemstones like diamonds, rubies, sapphires, and emeralds.
In Summary
Understanding these treatments and alternatives helps you make informed choices about gemstones, ensuring you know exactly what you're purchasing. Whether you're buying gemstones for their beauty, sentimental value, or investment, being aware of treatments and alternatives empowers you to shop confidently and knowledgeably, ensuring the best choices for your jewellery collection.