Thundereggs & Spherulitic Rhyolite (Rainforest Jasper)

Mt. Hay is the remains of an extinct ancient volcano, which was last active about 120 million years ago. When it was a rumbling volcano millions of gas bubbles were present in the molten rhyolite lava .. it is these gas ‘pockets’ that became thundereggs. Thundereggs or volcanic birthstones are the result of these “pockets” filling with siliceous liquids containing impurities and trace elements, which crystallize as they cool, and when cut in half, reveal many different colours and patterns.

Fossicking  –  (9:00am – 4:30pm)

Visitors can fossick through piles of thunderegg – bearing material which is excavated from the nearby mine site, and transported to a safe area suitable for all ages. Visitors are given a bag for their stones, a tool to fossick, and shown what to look for. Any stones collected can be kept, and upon completion of their search, each person can have a couple of stones cut for free. Extra cutting is available at extra cost. Fees apply for fossicking, and enclosed footwear is required. No fixed starting times or bookings required but we suggest arriving by 2pm at the latest to enjoy the full fossicking experience. Our hours of operation are 7 days a week, 9am to 4:30pm. Pets allowed if kept under control.


Adults: $30

Seniors: $27

Kids (5-17): $15

Under 5s: $5

Family Rate (2+2 or more) – 10% off total price

We are open 7 days a week – 9am to 4:30pm

We also cater for Student Groups! Email us for more info. Bookings are required. 


Closed in footwear MUST be worn when fossicking – no exceptions!

Gift Shop

Also on site is a gift shop with an extensive range of gemstone and pewter products, including souvenirs, gifts, gemstone jewellery, carvings etc. and “Aradon Fine Pewter” products, which are manufactured on site.

The kiosk sells cold drinks and ice creams. Visitors are encouraged to bring their own lunch. Open 7 days a week, 9:00am to 4:30pm.


Mount Hay Camping

Powered Site: 2 adults/1night $25 – $5 each additional person

Unpowered Site: 2 adults/1night $20 – $5 each additional person

Pets allowed (must be controlled)
Camp Fires are allowed
Basic Hot showers
Coin-operated Washing Machine