Kenneth A Russell

US Patent:

51462885, Sep 8, 1992

Filed:

Jun 19, 1991

Appl. No.:

7/717663

Inventors:

Kenneth M. Russell - Bethesda MD

International Classification:

G01N 2187

US Classification:

356 30

Abstract:

The invention relates to an apparatus for distinguishing cultured pearls from natural pearls by piercing the unidentified pearls with beams of light, preferably polarized, to reveal gross structural differences. The apparatus uses a light source, a polarizing filter, opaque shields, micro ports for light limitations, field magnifying lenses preferably 10. times. or 12. times. , and slides and other positioners to hold pearls singly or in strings.

US Patent:

52393542, Aug 24, 1993

Filed:

Sep 4, 1992

Appl. No.:

7/941175

Inventors:

Kenneth M. Russell - Bethesda MD

International Classification:

G01N 2187
G01B 1106

US Classification:

356 30

Abstract:

An apparatus comprising a light source, a lens system, a reticle illuminated by the light source, a housing having a substantially dark viewing chamber and a pearl holder for holding the cultured pearl in the substantially dark viewing chamber, and a reticle device for providing a reticle image observable through the lens system. The substantially dark viewing chamber is optically connected to the light source so as to allow light from the light source to traverse an aperture in the pearl holder to illuminate the pearl. The substantially dark viewing chamber is also optically connected to the lens system. In order to provide maximum contrast between light and darkness in the substantially dark viewing chamber, the housing is arranged to prevent entry of extraneous light into the substantially dark viewing chamber. A preferred method according to the present invention includes the following steps. A pearl is placed in the substantially dark viewing chamber.