Metal Detecting Guides & Reviews

How cavity detectors and ground scanners find tunnels and hollows, how professional geophysicists approach voids, what limits detection and how to confirm a cavity before you dig.

Handheld 3D ground scanners and ground penetrating radar both produce images of the subsurface, but they measure different things. Here is how they work, where each performs best and how to choose.

A practical guide to reading 3D ground scanner images: what the colors, peaks and dips mean, how metal and cavity signatures differ, and the checks that separate real targets from false readings.

A metal detector can only find shallow metal pipes and cables, not plastic lines. Learn how professional locators work and why you must call 811 before digging.

Metal detectors cannot detect groundwater. Learn the physics, the methods hydrologists actually use, and where electronic groundwater detectors fit in.

Steel safes and metal containers are detectable, paper cash is not. Learn which deep-seeking tools suit cache hunting and how to plan a realistic search.

Standard metal detectors cannot find non-metallic gemstones or crystals. Learn what they can find while rockhounding and which methods actually locate gems.

A metal detector cannot detect diamonds, only the metal in a ring setting. Here is the science, how diamonds are really found and what diamond detectors claim.

Copper is the benchmark conductor and reads high on detectors, while brass reads mid-range. Learn what to expect from coins, relics and native copper.