An Interview with Minelab Engineer Mark Lawrie
January 2018 by Chris Ralph
The design of metal detectors well-suited for prospecting is an interesting process and not necessarily an easy one to achieve. It is a combination that blends the desires of what prospectors would like, the requirements of sales people and dealers, with the science and physics of what the electronics can achieve.
Even with my favorite top-of-the-line gold detector there were several false digs. Many of the hot rocks gave a solid signal that was too much like a nugget to ignore. After trying several tests I just dug everything because it is better to be safe than leave a big, deep nugget for a more diligent gold hunter.
Depth is not an issue unless the site is thoroughly cleaned of shallow trash, and it is far easier to isolate and remove targets using a small coil in a target rich location.
I pulled out the nuggets I had worked on previously and looked at the size of the wire basket that the items to be cleaned are placed into. It looks much like a miniature french fry deep fryer.
Every year I go through this and every year it becomes more difficult to find new territory that is available for us to prospect. Is there anywhere that hasn’t been worked?
We decided to run a detector over each piece. If we got a decent signal we placed the piece into a high-grade pile and the rest went into another pile to be worked on later. This high-grade pile wasn’t that large—maybe 25 pounds...
It is the eighth largest brown diamond to be found and certified by park staff.
The Bawl Mill • Legislative and Regulatory Update • California: The Land of Big Nuggets—Part II • How to Interpret Assay Values • Bedrock Nugget Hunting: Tools of the Trade • A Primer on Bitcoin and Other Cryptocurrencies • Gold Hunting on Libby Creek • PLP and MMAC Update • Man's Best Friend • Third Largest Nugget in Existence Returns to Dallas • Melman on Gold & Silver • Mining Stock Quotes and Mineral & Metal Prices