Is your aura quartz real?

The colour is sprayed on. The stone under it is plain quartz

Aura quartz is not a mineral. It is ordinary quartz put in a sealed chamber and bonded with a whisper of metal, gold, titanium, platinum or silver. A few atoms thick. Shops have done this since the 1980s. The quartz is real. The colour is made. None of that is a crime if the seller tells you.

So the real question is not whether it is fake. It is whether you were told, and whether the coating is still whole.

Look at any chip, cut or drill hole

This is the test that settles it, and it takes five seconds. The coating only lands where the chamber could reach. Find a chipped tip, a sawn base or a drill hole and hold it to the light. Underneath you will see plain grey-white quartz, and a hard line where the colour stops. Natural colour runs all the way through a stone. A coating stops at the first crack.

Then run a finger over the tips and edges. On a piece that has been handled, the film wears thin there first and goes patchy or silver. A naturally rainbow stone does not go pale on its corners.

Sprayed rainbow versus the real kind

The lookalikes are labradorite, rainbow obsidian, bismuth and man-made opal. The difference is where the colour lives. Labradorite and rainbow obsidian flash from deep inside, along one plane. So the colour appears in a narrow slice as you turn it, and only in one patch. Aura coating covers the whole outside evenly and slides from teal to pink to gold as you turn it, like petrol on a puddle.

The other tell is how loud it is. Aura colours are brighter and more even than anything the ground makes. Aqua aura is a flat electric blue with a mirror shine. Angel aura is milky and pearly. If it looks like a soap bubble turned up to full, that came from a chamber, not a mine.

What it is not: opalite, dyed quartz, or plastic

Bismuth is grown, not mined, and it forms stepped hopper crystals that look nothing like a quartz prism. Synthetic opal shows an unnaturally regular columnar play of colour under a loupe. Dyed quartz, which sometimes gets sold alongside aura, shows colour trapped in fractures and a dead-uniform body rather than a surface film, and no iridescence at all. Plastic imitations give themselves away by weight and by warmth: quartz feels cold in the hand and takes a while to warm, plastic is warm immediately and much too light for its size.

Under the loupe, look for a mould seam. Quartz grows six-sided prisms with striations running across the faces at right angles to the long axis. No moulded imitation reproduces those striations correctly.

Care: the coating is the fragile part

The quartz is hardness 7 and will survive almost anything. The film will not. Do not soak it, do not put it in salt, and do not scrub it, because all three strip or dull the metal layer. No ultrasonic, no hot water, no elixirs. Wipe it with a dry soft cloth and keep it out of a pocket with keys. Sun does not fade the coating, but abrasion removes it, which is why a well-loved aura point looks paler at the tips after a year.

A fair price for a coated stone

Priced as what it is, treated quartz, aura material is inexpensive: the host is common Brazilian or Arkansan quartz and the coating is applied in batches in the United States, China, India and Brazil. If a piece is priced like fine natural gem rough, or described as ethically charged, ultra-rare or naturally rainbow, you are paying for the story. Buy it because you like how it looks, which is a perfectly good reason.