Defect of the Month

August, 2020
Nazca Desert Drawings
In the Kingdom of the Crystal Skull, Indiana Jones used (real) giant desert drawings to locate the (fictional) city of Akator. The unusual markings at the fracture origin shown here bear an eerie resemblance to the drawings created by the Nazcas, and are similarly shrouded in mystery. This particular origin was found at the inside knuckle of a glass container along with embedded material. Elemental analysis showed that the metal particulate was composed primarily of nickel and iron, likely caused by degradation of the plunger.
July, 2020
Bottle Opener
This crescent-shaped fracture typically occurs on bottles with a crown closure. Bottles broken during opening usually have a C-shaped fragment missing from the locking ring. This fracture pattern is usually caused when the consumer accidentally makes contact with the underside of the locking ring of the bottle with an opener rather than engaging just the cap.
June, 2020
Finish Line
This photomicrograph shows a top-down view of the sealing surface on a bottle. Three percussion cone flaws can be seen, of which one has extended into a crack across the finish. These percussion cones were caused by downward-directed impacts from a blunt object with a relatively small radius.
May, 2020
Blossoming Flower
This blossoming flower is actually crystalline calcium carbonate (Ca2O3) that has grown on the inside surface of a bottle. This crystal was the result of atmospheric weathering present on the surface and is somewhat unusual in size as compared to others on this bottle and what is normally identified as small hexagonal crystallites. The picture was taken at 2500 X and colorized according to elemental composition.
April, 2020
Hollow ACL Inclusions
Applied Ceramic Labels (ACL) are permanently bonded to glass containers by screen-printing a mixture of glassy material, pigment, and organic binder, then firing the container in a decorating lehr. The resultant label is highly wear and chemical resistant; however, defects such as this void can lower the surface strength of the glass container. Inclusions can also be caused by insufficient fusing temperatures, application issues, or raw material contamination. Because ACL is opaque and rather thin, light microscopy is of limited usefulness in finding these flaws. Consequently, SEM-EDX is the preferred imaging technique.