Coloured Stone Grading & Synthetics

At AGOVIA we prioritise the colour & cut of a stone over the presence of inclusions in the stone - this is because we believe that certain inclusions adds character to your stone, such as :

• Banding in a sapphire 
• Rutilated inclusion
• Colour zoning i.e, multicoloured 
  

At AGOVIA, we collaborate with expert stone cutters in Australia, Thailand and India, with a focus on precision cut and rich colour. This ensures every gemstone is completely unique in character, brilliance and beauty — no two are ever the same.

Gemstone treatments and what they mean: 

• Heat 
  • Heat treatment for sapphires (corundum) and certain forms of beryl (aquamarine, heliodor, morganite) is typically considered standard or acceptable practice. Heat treatment is used to improve stone colour, clarity, and vibrancy. Heat treatment can also reduce the presence or appearance of silk inclusions in sapphires and rubies.

• Oil
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    Oiling is a common treatment used to fill inclusions in emeralds. It is not permanent, so oiled gems require periodic maintenance. Emeralds — especially those that have been oiled — should never be exposed to household chemicals, ultrasonic cleaners, or sudden temperature changes (such as boiling water).

    During the process, an emerald is submerged in cedarwood oil, chosen for its similar refractive index. Standard treatments use colourless oil, while in recent years coloured oils have been applied to enhance hue or saturation. This is temporary and typically used on lower-quality material. Dyed emeralds hold little to no value, so caution is advised when purchasing from overseas or online sources.

• Beryllium Heat Treatment (infusion)

  • Beryllium treatment is specifically used to enhance the colour of sapphires and rubies (corundum), whereby a beryllium compound is introduced into the stones matrix during the heating process. Beryllium treatment is often used to create ultra-saturated shades of yellow, pink, orange or red. Beryllium treatment is semi-permanent, but often devalues the material as it is considered heavily 'treated'.

• Irradiation
  • Irradiation is the exposure of gemstones to ionizing radiation, altering their chemical structure to enhance colour. This process is done safely and can produce vibrant, typically permanent, colour changes. Gemstones typically irradiated include topaz and quartz.

• Glass or resin filling
  • This method of treatment is used to improve surface-reaching or internal inclusions; achieved through filling surface reaching fractues with lead glass or synthetic resin. AGOVIA does not use glass or resin filled gemstones as the treatment is not permanent and is an indicator of low quality gemstone material. 
    

Synthetic gemstones are created in controlled environments and share the same chemical and physical properties as their natural counterparts. Inclusions are rare in lab-grown stones, making them one of the key visual differences from natural gems.

Simulants (or imitations), on the other hand, may resemble natural gemstones in appearance but differ entirely in composition and structure.

Synthetic gemstones available at AGOVIA:

• Hydrothermal-emerald 
  
• Hydrothermal ruby
  
• Synthetic spinel
• Synthetic alexandrite

Both natural and lab-grown gemstones are beautiful and unique in their own way — the choice often comes down to personal preference and budget.