---
title: "Properties of marble, slate, amphibolite"
subject: "Engineering Geology I"
chapter: 4
key: "semester_3/engineering_geology_i:properties-of-marble-slate-amphibolite"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/properties-of-marble-slate-amphibolite
site: BCT Engineering
---

# Properties of marble, slate, amphibolite

Engineering Geology I · Chapter 4: Petrology

- Asked in: 2075 Asoj, 6 marks
- Video: [Metamorphic Rocks  - Lesson 8 - Part 6 of 6](https://www.youtube.com/watch?v=mW6zzzDN_uU) — mineguy101
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/properties-of-marble-slate-amphibolite
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-4

## Question

Write down the physical and engineering properties of marble, slate and amphibolite.

## Short answer

Marble: crystalline, hardness 3-4, strength 60-140 MPa, takes polish, used for flooring, cladding. Slate: fine-grained, slaty cleavage, anisotropic strength (50-100 MPa across), used for roofing, weak along cleavage. Amphibolite: dark, hard, tough, strength 100-250 MPa, good foundation and aggregate.

## Answer

#### Marble
- **Origin**: metamorphism (contact or regional) of limestone or dolomite.
- **Physical properties**: crystalline, granular ("sugary") texture; non-foliated; white, pink, grey or green with veins; hardness 3-4; specific gravity 2.6-2.8; effervesces with dilute HCl; takes a fine polish.
- **Engineering properties**: compressive strength 60-140 MPa; low porosity (under 1%); soluble in acidic water, reducing durability in polluted air; massive.
- **Uses**: flooring, wall cladding, steps, statues, monuments, decorative and ornamental stone, lime.

#### Slate
- **Origin**: low-grade regional metamorphism of shale or clay.
- **Physical properties**: very fine-grained, dense, dark grey, black, green or red; slaty cleavage, splits into thin, flat slabs; dull to slightly silky lustre; hardness 3-4; specific gravity 2.7-2.8.
- **Engineering properties**: compressive strength 50-100 MPa across the cleavage plane, but strongly anisotropic and weak along it; low water absorption; durable; fairly impermeable.
- **Uses**: roofing slates, flooring, damp-proof courses, paving, blackboards; it is poor for aggregate and weak for slopes and tunnels.

#### Amphibolite
- **Origin**: regional metamorphism of basic igneous rocks (basalt, gabbro) or impure carbonate rocks.
- **Physical properties**: medium- to coarse-grained, dark green to black; mainly hornblende and plagioclase; weakly foliated or massive; hardness 5-6; specific gravity 2.9-3.2.
- **Engineering properties**: hard, dense and tough; compressive strength 100-250 MPa; low porosity; good durability and resistance to abrasion, but weathers along foliation and joints.
- **Uses**: good foundation rock, aggregate, road metal, railway ballast, building and crushed stone.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Marble forms from
   A. shale
   B. basalt
   C. metamorphism of limestone or dolomite
   D. sandstone
   Answer: C. Slate is from shale; amphibolite from basic igneous. (Key point: Marble origin)

2. Slate is
   A. isotropic
   B. soluble
   C. glassy
   D. strongly anisotropic, weak along cleavage
   Answer: D. It splits into slabs. (Key point: Slate)

3. Amphibolite consists mainly of
   A. hornblende and plagioclase, dark and tough
   B. calcite
   C. quartz
   D. mica only
   Answer: A. Good foundation rock and aggregate. (Key point: Amphibolite)

4. Marble loses durability because
   A. it is foliated
   B. it dissolves in acidic water
   C. it is porous
   D. it swells
   Answer: B. Polluted air attacks calcite. (Key point: Marble weakness)

## Close variants set in other exams

- [Properties of marble, slate, granite](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aproperties-of-marble-slate-granite) — Engineering Geology I, chapter 4, asked 2×

## Related in Engineering Geology I

- [Properties of granite, limestone, shale, marble](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aproperties-of-granite-limestone-shale) — Engineering Geology I, chapter 4
- [Engineering significance of marble, granite, sandstone](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aengineering-significance-of-marble-granite) — Engineering Geology I, chapter 4
- [Engineering uses of granite and marble](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aengineering-uses-of-granite-and) — Engineering Geology I, chapter 4
- [Engineering significance of marble](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aengineering-significance-of-marble) — Engineering Geology I, chapter 4
- [Physical properties of minerals](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aphysical-properties-of-minerals) — Engineering Geology I, chapter 3, asked 6×
- [Physical and optical properties of minerals](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aphysical-and-optical-properties-of) — Engineering Geology I, chapter 3, asked 2×

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- [Important properties of civil engineering materials](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aimportant-properties-civil-materials) — Civil Engineering Materials, chapter 1, asked 8×