Carbide Scriber Views
“We decided to put the carbide scriber to the test,” explained Matlins, “because research by several gem testing laboratories revealed that the coating on surface-coated stones could be scratched by a carbide scriber.” By taking a carbide scriber – a simple tool that looks like a pen – and dragging its carbide point across one of the facets, the point will scratch through the coating. It won’t scratch the diamond, just the coating, which can be seen immediately with the loupe.
To test this observation, each participant at the conference was given a high quality carbide scriber to use on the diamonds they were examining. They scratched crown facets and pavilion facets. In the case of the fancy-colored diamonds examined, in 100% of cases where the diamond had been surface coated, the carbide scriber quickly and easily revealed it. Facets on the crown as well as the pavilion were tested and revealed that all of the surface-coated colored diamonds were coated on the pavilion only—no “scratches” appeared on the crown facets, but “scratches” did appear on pavilion facets. The tell-tale scratch was immediately visible with the loupe.
Smith and Koivula also pointed out that coating techniques are not new and were used over 50 years ago to make diamonds appear whiter; the technique could improve color by 6 – 7 grades. These stones are referred to as painted diamonds, and they still pop up in the market, in every size and shape. They will not have a laboratory report from GIA or other respected labs, because the labs won’t issue reports on such stones, but they can have a counterfeit report. Painted diamonds may have a coating over the entire stone, or just the pavilion, or simply around the girdle. The AGA did not have any of these stones to test, but gemologists present who had encountered such stones confirmed that the carbide scriber also scratched the surface coatings used to produce them. They pointed out that the coatings were often applied to the entire diamond, but could also be on just the pavilion, or crown or the coating might have been applied only to the girdle area.
Carbide tip point reverses for safety to Alnico permanent magnet on other end. Replaceable carbide point for marking and scribing stainless steel, ceramics and glass. Has a convenient pocket clip and a screw chuck for reversing point when not in use. This Magnetic Carbide Scriber is one of many top quality items in our Scribers m Butt Markers department.
Carbide Scriber Images
