Forensic Physics: Glass Types and Composition Basics
Published:
Questions
30
Duration
30 min
Faculty-reviewed
0
Updated
25 May 2026
About this mock
UGC-NET Forensic Science Unit VII drill on glass classification, composition, and physical properties as trace evidence. Covers the four principal glass types encountered in forensic casework: soda-lime glass (windows, bottles, refractive index 1.51-1.52), borosilicate glass such as Pyrex (laboratory ware and headlamps, RI approximately 1.47), tempered or toughened glass (vehicle side windows, dice fracture pattern), and laminated safety glass (windshields, polyvinyl butyral interlayer). Additional types include lead crystal glass (tableware, high PbO content) and multilayer bulletproof or armoured glass. The Pilkington float process, by which most flat glass is manufactured by floating molten glass on a tin bath, is examined as a process fundamental. Refractive index ranges across glass types provide the principal discriminating property used by forensic examiners, alongside density and elemental composition.
The Indian forensic context addresses glass examination as practised at the Central Forensic Science Laboratory (CFSL), Chandigarh and Kolkata, under ASTM E1967 (refractive index of glass by oil immersion and phase contrast microscopy) and ASTM E2926 (LIBS elemental analysis of glass). Saferstein's Criminalistics (12th edition) and Sharma B.R.'s Forensic Science in Criminal Investigation and Trials are the primary textbook references. Glass fragments from windshields, side windows, headlamp lenses, bottles, and spectacle lenses represent the most common forensic submissions, and identification of glass type aids in hit-and-run reconstruction, building entry analysis, and contact trace interpretation under Locard's exchange principle.
Topics covered:
- Soda-lime glass: SiO2, Na2O, CaO composition and RI 1.51-1.52
- Borosilicate glass (Pyrex): B2O3 content, RI approximately 1.47
- Tempered glass: thermal treatment and dice fracture pattern
- Laminated glass: PVB interlayer and windshield application
- Bulletproof and armoured glass: multilayer polycarbonate construction
- Float process (Pilkington): molten glass on tin bath
- Lead crystal glass: PbO content and high RI
- Forensic glass sources: windows, headlamps, bottles, spectacles
Calibrated for first-pass UGC-NET Forensic Science Paper II preparation and NFSU MSc Forensic Chemistry entrance revision. Allow 30 minutes.
Sources & references
Questions in this mock are written and verified against the following sources. Citations are recorded per question and shown in the explanation after submission.
- cited in 14 questions
Saferstein, Richard — Criminalistics: An Introduction to Forensic Science, 12th Edition, Pearson
Chapter on Trace Evidence: Glass — armoured and ballistic-resistant glass construction
- cited in 9 questions
Sharma, B.R. — Forensic Science in Criminal Investigation and Trials, 4th Edition
Chapter on Glass Evidence — laminated windshield use, forensic fracture pattern analysis
- cited in 5 questions
Koons, Robert D. and Buscaglia, JoAnn — Forensic significance of glass composition and refractive index measurements, Journal of Forensic Sciences
Discriminating power of refractive index in forensic glass comparison databases
- cited in 1 question
ASTM E2926 — Standard Test Method for the Forensic Analysis of Glass by Laser-Induced Breakdown Spectroscopy
Full standard; LIBS elemental fingerprinting of glass for forensic discrimination
- cited in 1 question
ASTM E1967 — Standard Test Method for the Automated Determination of Refractive Index of Glass Samples Using the Oil Immersion Method and a Phase Contrast Microscope
Full standard; hot-stage oil immersion GRIM3 methodology
How our mocks are built
Questions are written and edited by the ForensicSpot team and cited from peer-reviewed forensic textbooks, official syllabi and primary case law. Each one is verified before publishing. Detailed explanations show after you submit, so the test stays a real test. See a mistake? Tell us.
Common questions
What does the Forensic Physics: Glass Types and Composition Basics mock cover?+
UGC-NET Forensic Science Unit VII drill on glass classification, composition, and physical properties as trace evidence. Covers the four principal glass types encountered in forensic casework: soda-lime glass (windows, bottles, refractive index 1.51-1.52), borosilicate glass such as Pyrex (laboratory ware and headlamps, RI approximately 1.47), tempered or toughened glass (vehicle side windows, dice fracture pattern), and laminated safety glass (windshields, polyvinyl butyral interlayer). Additio
How many questions and how long is the test?+
30 multiple-choice questions, 30 minutes total. Difficulty: easy. Tier: Premium.
Who is this mock for?+
Forensic science students and aspirants who want timed, exam-style practice with explanations and verified source citations on Forensic Physics, NET. Useful for postgraduate entrance preparation and for BSc / MSc forensic students testing their recall under time.
Are the questions reviewed?+
Each question carries a verified source citation. Faculty review for individual questions is in progress.
Do I need an account to take this mock?+
Yes, a free ForensicSpot account is required to start a timed attempt — this lets you save progress, see per-question explanations after submission, and track your topic-level performance over time.