Pease & Curren lab evaluated three different gold testers and the results may surprise you.
What we evaluated:
- an inexpensive 6-acid test kitfrom Star Struck LLC
- a low-priced electronic tester, ET18 from R S Mizar
- a high-priced electronic tester, GXL-24PRO by TRI Electronics.
We chose pieces of 10K, 14K, and 18K gold (both white and yellow), silver, and gold plated silver. Prior to testing, we used a table-mounted Innov-X Alpha XRF unit to verify the composition of each piece. Each piece was tested first on the surface with no preparation, then with surface preparation as prescribed by the tester’s manufacturer.
|Star Struck6-Acid Test Kit||RS Mizar ET18 Electronic Tester||TRI Electronics GXL-24PRO Electronic Tester|
|10 K prepped||accurate||not accurate||tested lower|
|14K||accurate||not accurate||tested lower|
|14K prepped||accurate||not accurate||tested lower|
|18K||not consistent||not accurate||tested higher (19-23K)|
|18K prepped||not consistent||not accurate||tested higher (18-20K)|
|Silver prepped||accurate||not accurate||accurate|
|Gold Plated Silver||surface accurate||not tested||surface tested lower|
|Gold Plated Silver prepped||accurate except on chain||not tested||inconsistent|
|Gold Filled||surface accurate||not tested||surface inconsistent|
|Gold Filled prepped||indicates not karat||not tested||not accurate|
Bottom line: Hands down, the most consistent of the testers was the acid test kit. Neither of the electronic testers was up to par, and the least accurate of the testers was the ET18.
What does this mean for our customers?
We recommend using caution when performing tests on unknown karat gold pieces as virtually all testers (including X-ray) can be fooled by surface layers that don’t reflect the composition of the base metal. For the most accurate results, scratch the surface before testing, and use an acid test kit as recommended by the manufacturer.