The search for rare rocks and minerals is like a treasure hunt, Olga Nicholson says.
She had one of the stalls at the Wanganui Rock and Mineral Club's show on April 21 and 22. She's from the Coromandel, and her collection was mainly New Zealand minerals she has found herself.
"You never know what you are going to find. They don't come out of the ground looking beautiful like this. You've got a lot of cleaning and you have to know what you're looking for," she said.
She's searched on forestry land and bush land, and said it was essential to get permission before rock-hunting on private land.
"We are always very stringent with our club."
Some landowners had been put off by people digging up farm tracks, and were reluctant to give permission. One was asking $50 per car for the club to hunt on private land near Rotorua.
Club president Dave Blakemore specialises in minerals for collectors. He's been to China four times, and bought minerals there. He also goes to shows in the United States.
The Whanganui show included stalls with jewellery and bone carving, and a stall with crystals used for healing.
Neither Blakemore nor Nicholson believe they can heal - though Nicholson had a strange experience with a piece of chert held to her forehead once, and she said quartz crystals let sound waves pass through without distorting them.
"I believe the majority [of the healing] is in your own mind. If a piece of rose quartz in your pocket works well for you, then keep taking your medication," Blakemore said.
Ted and Betty Duggan are in their 90s and are lifelong members. They've been out looking for minerals, and also cut and shape them.
"Our son got us into it when he was 8. He is 50-odd now and he's still mad on rocks," Betty Duggan said.
About 300 people visited the show on Saturday. It's put on by the club every two years. The Palmerston North club runs it in the alternate year.
The club has about 15 members, and meets monthly.