Jeweller’s Guide to Zircon: Identification Tips and Jewellery Making Advice
Zircon is one of my favourite gemstones, and not just for its radiant brilliance, but because of its extraordinary history. Some zircon crystals are among the oldest materials ever found on Earth, dating back over 4 billion years. It’s a gem with deep roots and dazzling beauty, making it a fascinating choice for jewellers and collectors alike.
Often mistaken for diamond due to its exceptional sparkle, zircon is a gemstone known for its wide colour range and complex optical properties. While it’s especially cherished in earthy tones like honey-brown and golden-orange, blue remains the most popular due to its birthstone status.
Here’s everything you need to know about identifying and designing with this ancient gemstone.
Basic Identification Information
Name & Synonyms:
Zircon
Species:
Zircon
Colour Range:
Blue, colourless, golden-brown, orange, red, pink, green, yellow, purple (rare)
Refractive Index:
1.780 – 2.024
Birefringence:
0.000 to 0.059
(High birefringence in many stones creates visible doubling of facets)
Optical Sign:
Uniaxial +
Pleochroism:
Weak with 2 colours
Blue Zircon - Deep sky blue and colorless to yellowish gray.
Red Zircon - Red and clove brown.
Brown Zircon - Reddish brown and yellowish brown.
Specific Gravity:
3.90 to 4.73
Fluorescence:
Often inert, but some stones (yellow, orange, red and blue) may fluoresce under UV
Lustre:
Vitreous (glass like) to adamantine (diamond-like)
Clarity:
Type I to 2 (falls somewhere in the middle)
While many stones may be eye clean, it's just as common to find stones that are visibly included
Gems Often Mistaken for Zircon:
Cubic zirconia (CZ), diamond, sapphire, topaz, spinel
Mohs Hardness:
6 to 7.5
(Natural zircon is relatively hard but can be brittle—treat with care)
Wearability:
Fair to Good
Birthstone:
December (alongside turquoise and tanzanite)
Spotting Synthetic (Lab-Grown) Zircon
Unlike many other popular gems, synthetic zircon is extremely rare within the jewellery market. Its popularity has been overshadowed by cubic zirconia, which is a completely unrelated material despite the similar name.
If a gem is labelled as “zircon” but seems flawless, overly brilliant, or suspiciously cheap, double-check that it’s not cubic zirconia (CZ).
Common Treatments
Heat treatment is extremely common in zircon and usually accepted in the trade. Most blue and colourless zircons on the market have been heated to remove brown overtones and improve clarity.
Heat treatment is stable and permanent, though it can make the stone slightly more brittle.
Durability Considerations
Zircon has imperfect cleavage. Its brittleness means it can chip or abrade along facet edges, particularly when exposed to frequent wear. Stones should be set securely and protected from harsh knocks.
Rapid changes in temperature should also be avoided, as they can cause internal stress or even fracture in some cases. Ultrasonic and steam cleaning are not recommended for zircon due to this.
Jeweller’s Setting Tips
Because of its lower hardness and cleavage, zircon benefits from protective settings, especially in rings. Bezel and halo settings are excellent options.
Zircon’s fire and sparkle shine best in well-lit, open settings, but prong settings should hold the stone firmly without putting pressure on corners or thin edges.
For blue zircon, white metals like silver, platinum, or white gold will enhance its cool tones, while yellow gold adds warmth to golden or brown stones.
Use gentle tools and avoid over-tightening settings, especially with heat-treated stones.
Due to its brittleness, zircon should be handled with care during polishing and finishing.
Care Instructions
Cleaning:
Warm water and mild soap are safest. Use a soft brush for detailing.
Avoid ultrasonic or steam cleaning, as heat-treated zircons can be sensitive.
Storage:
Store separately from harder stones to prevent abrasion. Wrap in a soft cloth or padded compartment.
Daily Wear:
Zircon is ideal for earrings, pendants, brooches and other low-contact pieces. When it comes to rings, zircon is best reserved for occasional wear or protected designs.
Market & Ethical Notes
Zircon is relatively affordable compared to other natural gemstones, particularly in smaller sizes or less popular colours. Fine blue or vibrant red zircons, however, can fetch higher prices due to rarity and visual appeal.
Major sources include Cambodia, Sri Lanka, Myanmar, Vietnam, and Tanzania. Blue zircon is often mined in Cambodia before undergoing heat treatment to achieve its final colour.
Symbolic & Spiritual Meanings
Zircon is associated with wisdom, grounding, and clarity. Its long history makes it a stone of ancient memory and cosmic connection, especially in spiritual practices that work with Earth energy.
Blue zircon is said to align with the throat chakra, encouraging communication and truth. Golden and brown zircons may link to the solar plexus or root chakras, supporting confidence and stability.
Etymology
The name “zircon” is believed to derive from the Persian word zargun, meaning “gold-coloured.” Though modern zircon can be found in many colours, golden-brown hues are some of the most traditional.