Pink sapphires are a beautiful and rare gemstone variety of the mineral corundum. They can range from very light pink to deep pinkish red in color. Identifying a true pink sapphire can be difficult due to the existence of many pink gemstone simulants and treatments that can alter the appearance of a stone. This article will provide an in-depth guide on how to properly identify a natural and untreated pink sapphire.
What Causes the Pink Color in Sapphires?
The pink color in sapphires is caused by trace amounts of chromium and iron within the stone’s crystal structure. The chromium produces the actual pink hue, while iron influences the saturation of the color. The more chromium present, the deeper and more saturated the pink color will be. Less chromium results in very light pink shades.
Common Characteristics of Natural Pink Sapphires
Some common characteristics of untreated, natural pink sapphires include:
- Medium to medium-dark pink hue – Natural pink sapphires rarely occur in very light or extremely dark reddish pink hues.
- Even color distribution – The color should appear consistent throughout the stone under magnification.
- Presence of silk – Tiny rutile mineral inclusions that resemble silk threads are common in pink sapphires.
- Natural inclusions – Inclusions indigenous to the original host rock like crystals, clouds, and feathery fingerprints indicate natural origin.
- Moderate saturation – Overly intense hot pink coloration may indicate treatment.
- Moderate transparency – Natural pink sapphires tend to have good clarity but not be entirely transparent.
Common Treatments and Simulants
There are a few common methods used to alter the color and clarity of pink sapphires on the market:
- Heat treatment – Heat treating blue sapphires is a common way to produce pink sapphires. This process involves heating stones to over 1,600°C to induce pink coloration.
- Beryllium treatment – Beryllium can be diffused into a sapphire to produce a vivid pink color. This is considered a form of treatment.
- Radiation treatment – Exposing colorless sapphires to radiation can induce a pink hue similar to heat treatment.
- Filling – Fractures and cavities may be filled with a pink-tinted glass or resin to improve transparency.
- Dyeing – A pink dye or stain can be applied to the surface of the stone or absorbed into pores to create a pink appearance.
There are also many simulants that can imitate the look of pink sapphire:
- Pink spinel – Often indistinguishable from pink sapphire visually. Only advanced testing can separate them.
- Pink tourmaline – Can display vivid pink shades similar to fine pink sapphire.
- Pink topaz – Typically lighter and softer in tone compared to pink sapphire.
- Pink garnet – Rhodolite garnet has a pale pinkish purple hue.
- Pink quartz – Most often appears very light pink and slightly milky.
Advanced Testing Methods
To conclusively identify a high quality natural pink sapphire, advanced gemological testing is recommended. Some methods include:
- Microscopy – Illuminating the stone to view inclusions and indicators of treatments.
- Spectroscopy – Measures optical properties to detect enhancements and simulants.
- Chemical analysis – Detects foreign chemical elements used in treatments.
- Photoluminescence – Reveals natural vs induced colors by exposing to UV light.
Summary of Key Identification Points
Here is a summary of the most important indicators to identify an untreated natural pink sapphire:
|Color hue||Medium pink to pinkish red. Avoid very pale or extremely vivid hues.|
|Color distribution||Even color saturation throughout the stone.|
|Clarity characteristics||Natural inclusions like silk and fingerprints. Avoid totally clean stones.|
|Transparency||Good translucency but not completely transparent.|
|Advanced testing||Can detect any undisclosed treatments or simulants.|
Identifying Quality Factors
Once the authenticity of a pink sapphire is verified, identifying quality factors is important for assessing value. Key characteristics to look for include:
- Color saturation – Deeply saturated pink gems are most desirable. Pale pink sapphires are less valuable.
- Clarity rating – Eye clean stones with minor inclusions command higher prices. Cloudy or heavily included stones are less prized.
- Cut quality – Well-cut gems with superb polish and symmetry show the most vivid pink color.
- Carat weight – Larger pink sapphires are exponentially rarer and more expensive.
By understanding what signs to look for, you can identify high quality natural pink sapphires and find stones that match your preferences. Consult an expert gemologist if ever in doubt about a significant pink sapphire purchase.
Where to Source Reputable Pink Sapphires
The best places to source authentic, quality pink sapphires include:
- High-end jewelry retailers and designer brands
- Established auction houses like Sotheby’s and Christie’s
- Gemological Institute of America (GIA) accredited jewelers
- American Gem Society (AGS) member stores
- Online vendors with independent gemological certification
Always request a gemological report from a respected lab like GIA or AGS to verify any major pink sapphire purchase. An accredited appraisal will confirm the important quality factors and disclose any detectable treatments.
Identifying natural pink sapphires takes careful inspection of color, clarity, inclusions and cutting quality. Advanced testing is recommended to screen for undisclosed treatments or simulants. Once certified, judging the characteristics of color saturation, clarity, cut and carat weight will reveal the true quality. Sourcing stones from reputable sellers that provide independent appraisals ensures the best chance of buying a genuine pink sapphire. Understanding these identification methods allows buyers to make informed decisions and find the highest quality pink sapphires.