Not a diamond; these are coated or treated glass rhinestones (commonly known as Aurora Borealis or AB crystals) set in vintage costume jewelry.
Not a diamond; these are coated or treated glass rhinestones (commonly known as Aurora Borealis or AB crystals) set in vintage costume jewelry. · Mixed (primarily round chatons and small marquise/navette rhinestones)
Not applicable (machine-molded or pressed glass facets rather than precision gemstone faceting) Cut
Carat
Not applicable (glass/rhinestone composition with no gemological carat weight)
Color
Not applicable (displays an iridescent Aurora Borealis rainbow coating over a clear or slightly tinted glass substrate)
Clarity
Not applicable (typical costume-grade glass containing internal bubbles and mold lines rather than diamond inclusions)
Shape
Mixed (primarily round chatons and small marquise/navette rhinestones)
Overall Assessment
The item is a charming mid-century vintage costume brooch featuring iridescent Aurora Borealis rhinestones mounted in a textured gold-tone metal frame. While visually striking due to its colorful flashes, it contains no diamonds or precious gemstones.
Cut Quality
Not applicable (machine-molded or pressed glass facets rather than precision gemstone faceting)
Brilliance
Moderate to low white light return due to the nature of glass and surface coating interference
Fire
High multicolored spectral dispersion produced entirely by the specialized AB surface coating
Scintillation
Flashes of multi-colored light from the iridescent coating when moved under light sources
Proportions
Standard standard-depth machine-pressed chaton proportions intended for costume settings
Symmetry
Fair to Good relative to mid-century costume jewelry manufacturing standards
Polish
Moderate surface luster typical of vintage pressed glass with foil or vapor-deposited coatings
Fluorescence
Not applicable (strong iridescent surface reflection mimics spectral effects but is not standard diamond fluorescence)
Inclusions
Internal gas bubbles and flow lines characteristic of glass manufacture
Blemishes
Minor surface wear, abrasion, and potential coating loss on the iridescent layer due to age
Origin
Mid-20th century mass-produced costume jewelry, likely originating from Europe (such as Austria or Czechoslovakia) or the United States
Treatment Detection
Surface-applied vacuum-deposited metallic coating (Aurora Borealis treatment pioneered by Swarovski in the 1950s)
Estimated Value
Low collectible value (typically $20 to $75 USD depending on maker, era, and overall condition of the brooch)
Certification Estimate
Not certifiable by major gemological laboratories (GIA, AGS, IGI) as these are not diamonds or genuine gemstones
Investment Potential
Nominal investment value; collected strictly for vintage fashion, aesthetic appeal, and historical costume jewelry interest
Similar Diamonds
None (completely distinct material class)
Setting Suggestions
Already set in a vintage gold-tone metal mesh and prong setting typical of mid-century brooches
Care & Maintenance
Avoid all liquid immersion, ultrasonic cleaners, and harsh chemicals, as moisture and solvents can strip the delicate surface coating; clean only with a soft, dry cloth
Interesting Facts
The Aurora Borealis (AB) coating was developed in 1955 through a collaboration between Crystal Glass Works Swarovski and Christian Dior to mimic the northern lights on clear crystal stones