The flashcards below were created by user
on FreezingBlue Flashcards.
Hard (transparent~translucent), brittle material; made from molten inorganic material; non-crystalline
What is the forensic value of glass?
- - Ubiquitous
- - Stable
- - Easily broken and transferred
Name and provide examples of compositional classes of glass.
- Soda lime glass
- - light bulbs
- - bottles/containers
- - headlamps
- Borosilicate glass
- - pyrex
- Lead-alkali glass
- - crystal
What is soda lime glass composed of?
Sand, soda and lime
Name three different glass products of automobiles. Explain how they differ.
- - heated and rapidly cooled
- - side and back windows
- - plastic sandwich
- - windshield
- - aluminum/chromium
- - side mirrors
Explain how the physical shape of an impact crater can be used to determine which direction a projectile was traveling.
Narrow opening is the entry side; keyhole effect
Recognize and distinguish radial and concentric (tangential) fracture lines in a glass fracture.
- - radiate outward from center of point of force
- Concentric (tangential)
- - encircle/form a polyhedron around point of force
State the 4R rule for glass fracture patterns.
RIB marks on RADIAL cracks form RIGHT angles on the REVERSE side of the glass to that struck by a projectile.
Name 6 features and/or properties of glass that are typically determined in the forensic examination of this evidence.
- Surface features
- Physical match
- Refracive index
Describe two experimental approaches that can be used to determine the RI for a piece of glass.
- Using GRIM
- Vacuum/air and liquid/solid