Where Does Green Zircon Come From
Green zircon originates from select locations across the globe that provide ideal conditions for these rare gemstones to form. The source mine plays an important role in determining overall quality and value.
Sri Lanka
Sri Lankan green zircons are considered the world standard due to their balanced combination of rich color, clarity, and size.
Sri Lanka is renowned for being the world's leading source of these gems. Deep forest greens with high clarity make Sri Lankan zircons a standout among others.
They are also significant suppliers of large carats of zircon specimens. The 9.99-carat record-setting zircon was mined in Sri Lanka.
Burma
Burmese stones have attractive green colors, but they lack dimensions.
They are also a second major supplier in the global market. Zircons from Burma have paler hues, yet they are still transparent. In terms of size, they are smaller compared to Sri Lankan stones.
Heat treatment is commonly used to enhance the color of Burmese stones.
Other Sources
Specimens from other localities have yet to match the quality benchmarks set by Sri Lanka and Burma.
- Australia – dark yellowish greens, opaque, low clarity
- Kenya – light tone, significant inclusions
- Tanzania – emerald tones, small sizes under 5 ct
- Nigeria – high clarity but very light green/yellow
When purchasing green zircons, source origin serves as a key indicator of potential zircon value and investment quality. The discerning collector looks for certifications confirming the source along with accompanying gemological reports.
Properties
Green zircon has a unique set of physical properties and chemical composition that distinguishes it from other colored gem varieties in nature.
Crystal Structure
Green zircon forms in the tetragonal crystal system. Tetragonal prisms are terminated by tetragonal dipyramids. It may contain some secondary nodules and inclusion crystals.
Hardness & Durability
The hardness of green zircon measures 6.5 to 7.5 on the Mohs hardness scale. This gemstone is durable for everyday wear when set appropriately.
However, it is softer than sapphire and ruby.
Chemical Composition
Green zircon has the following chemical formula – ZrSiO4 or zirconium silicate. It often includes traces of hafnium, uranium, and thorium
Impurities of a gemstone impact coloration and properties
Key Chemical Components
|
Component |
Chemical Formula |
Role & Effects |
|
Zirconium |
Zr |
An essential part of crystal structure |
|
Silicate |
SiO4 |
The main constituent of molecular formula |
|
Hafnium |
Hf |
Helps form blue and green colors |
|
Uranium |
U |
Causes yellow and green tints |
|
Thorium |
Th |
Linked to red and brown hues |
The combination of zirconium, silicates, and varying levels of elements like hafnium and uranium lend green zircon its signature green color ranges. While chemically complex, these trace elements allow it to form in vivid green hues unseen in many other natural gems.
How is Green Zircon Improved by Treatments
While a rare few possess standout color and clarity right out of the ground, the vast majority of gem-quality green zircons undergo special treatments to improve appearance and marketability.
The most common enhancement process uses heat to intensify color hues and minimize flaws.
Heat Treatment
The temperature for Zitrin heat treatment is between 900 °C and 1500 °C. It removes impurities and enhances color saturation.
The process helps minimize flaws and cracks by "healing" the crystal structure. Most of the world's supply of gemstones is heat-treated. Some collectors still prefer to keep their items untreated. It's difficult to find untreated green zircons larger than 1 carat.
Low Heat Treatment
There is an alternative type of treatment on lower temperatures from 500°C to 900°C under oxidizing conditions. This alternative treatment is less intense than standard heat treatments, but many traders consider it a minor enhancement.
Irradiation
Irradiation exposes stones to radiation to alter color. This is an uncommon technique for green zircon. Irradiation is also known to produce radioactivity which is unsafe for jewelry.
Impact of Treatments on Costs
|
Treatment |
Rarity |
Color Quality |
Value |
|
Untreated |
Very Rare |
Average |
Higher premiums |
|
Low Heat |
Uncommon |
Good |
Moderate pricing |
|
Heat Treated |
Widely available |
Best |
Discounts applied |
When searching for investment-grade green zircon it is advisable to opt for untreated or low heat-treated stones with accompanying certification. Otherwise, heating is an accepted practice that helps yield stunning green colors.
Our jewelry store, vividcarat.com, provides fair and comprehensive data about treatments of gemstones available in our stock in New York City.
The 4 C’s of Green Zircon
The value of green zircon is determined by several key factors:
Color
The most valued green zircons have a deep, intense, even green hue.
Light and dull tones are less desirable and decrease value. Secondary colors like yellow, brown, or gray also reduce prices per carat.
Clarity
Clear specimens with high transparency are preferred. Inclusions and blemishes that impact clarity decrease costs.
Cut
Well-proportioned cuts enhance the brilliance of green zircons. Poor cuts are bad for investments.
Carat Weight
Larger gemstones over 5 carats command higher prices per carat. Premium prices paid for rare large specimens over 10 carats
Notable Examples of Green Zircon Ever Purchased
- A 9.99 ct natural green zircon mined in Sri Lanka sold for over $10,000 per carat
- A 6.05 ct specimen from Tanzania fetched $7,150 per carat
How to Verify Green Zircon Authenticity in New York City
Reputable gemstone certification offers buyers confidence by accurately appraising quality factors and assuring a green zircon is natural and untreated. These institutes have exacting analysis protocols to separate synthetic stones from high-value natural gems.
Benefits of Certification
- Confirms geographic origin
- Evaluates quality characteristics
- Detects any treatments or enhancements
- Screens for artificial products
- Supports investment value
Leading Certification Labs
- GIA – Gemological Institute of America
- AGL – American Gemological Laboratories
- GRS – Gem Research Swisslab
- Lotus – Asia’s premier certification institute
When selecting a green zircon in New York City, look for an accompanying certificate from one of these internationally recognized gem labs.
Key Details Included on Certificates
- Weight–carat mass
- Measurements – cut dimensions
- Color – hue, tone, saturation
- Clarity – flaws, inclusions
- Cut – the quality of faceting
- Treatments – any enhancement methods
- Comments – additional relevant details
Reputable dealers only sell certified natural gems with grading reports that accurately detail the overall quality relative to pricing.
Transparent reporting builds trust in the seller and confidence in the acquisition for both novice and expert collectors alike. Investing in uncertified stones from disreputable sources carries a substantial risk and should be avoided.
Our jewelry store in New York City offers a transparent policy regarding treatments of loose gemstones or jewelry with gemstone inlays to ensure that you make an informed purchase decision.