Blue aventurine is a beautiful semiprecious stone that has captivated people for centuries with its soothing blue-green color. But is this stone completely natural or is its color enhanced artificially? Let's take a closer look at the origins and properties of blue aventurine.
How Does Aventurine Form?
Natural aventurine forms when quartz crystallizes with embedded fuchsite (for green aventurine) or other mineral inclusions that provide its color. The minerals mica and hematite are responsible for the shimmering aventurescence effect.
Aventurine is found in India, Spain, Russia, Tanzania, and a few locations in the US including Pennsylvania and Oregon. The most sought-after aventurine comes from India.
What About Blue Aventurine?
Blue aventurine is considered one of the rarer and more desirable colors of this stone. But natural blue aventurine is very uncommon. Most blue aventurine is produced by heat treating green aventurine or gray quartz. This process enhances the blue tones of the stone.
Genuine blue aventurine does exist, though it is quite rare. Natural blue aventurine forms when quartz contains inclusions of dumortierite, a fibrous blue mineral. Only a small number of mines worldwide produce the natural blue variety.
How to Tell if it's Natural?
There are a few ways to identify if a piece of blue aventurine is natural or color enhanced:
- Examine closely under magnification to look for uniform blue fibrous structures. These are inclusions of dumortierite that indicate natural blue aventurine.
- Look for a range of blue and green tones rather than an overall pure blue. Natural stones show more variation.
- Check for signs of treatment like concentrated blue patches or soft rounded edges on stripes of blue. Heated aventurine shows more unnatural patterning.
- Natural blue aventurine is typically opaque and duller, while synthetic stones are more transparent and vivid.
- Ask the seller directly about the stone's origins and any treatments. Reputable dealers will disclose this information.
In the end, genuinely natural blue aventurine is hard to come by. But with close inspection and a trustworthy supplier, you can find this rare, serene stone that formed beautifully over millions of years underground. Most blue aventurine, though enhanced, retains the elegant look and feel that makes this gemstone so popular.
