PHYSICAL IDENTIFICATIO

N OF MINERALST.HARISH

DEFINITION OF MINERAL A MINERAL IS A NATURAL,INORGANIC SOLID,HOMOGENOUS SUBSTANCE WITH DEFINITE CHEMICAL COMPOSITION AND REGULAR ATOMIC STRUCTURE.

METHODS OF STUDY OF MINERALS X-RAY ANALYSIS CHEMICAL ANALYSIS OPTICAL STUDY STUDY OF PHYSICAL PROPERTIES (BY LABORATORY STUDY)

LABORATORY STUDY IN LABORATORIES MINERALS ARE IDENTIFIED PREFERABLY BY FOLLOWING THE METHOD OF STUDY OF PHYSICAL PROPERTIES OF MINERALS.

ADVANTAGES LEAST EXPENSIVE. NO LOSS OF MATERIAL-HENCE REPETITIVE STUDY IS POSSIBLE.

IMMEDIATE INFERENCE. SIMPLE STUDY AND REASONABLY CORRECT INFERENCES ARE POSSIBLE BY THIS METHOD.

PHYSICAL PROPERTIES OF MINERALS COLOUR:-IT IS THE USUAL BODY

COLOUR OF MINERAL. FORM:-IT IS USUAL MODE OF

OCCURRENCE OF MINERAL IN NATURE. STREAK:-IT IS COLOUR OF MINERAL

POWDER;TESTED,BY RUBBING THE MINERAL ON STREAK PLATE.

LUSTRE:-IT IS THE SHINNING OBSERVED ON MINERAL SURFACE.

FRACTURE:-IT IS THE NATURE OF BROKEN SURFACE OF A MINERAL.

PHYSICAL PROPERTIES OF MINERALS CLEAVAGE:-IT IS THE TENDENCY OF

MINERAL TO SPLIT EASILY ALONG A PARTICULAR PLANE,WHICH IS A PLANE OF WEAKNESS BY VIRTUE OF ITS ATOMIC STRUCTURE.

HARDNESS:-Hardness is measured by the resistance which a smooth surface offers to abrasion. The degree of hardness is determined by observing the comparative ease or difficulty which one mineral is scratched by another.

It is determined with the help of moh’s scale.

PHYSICAL PROPERTIES OF MINERALS Moh’s scale consists of a set of ten

reference minerals arranged in increasing order of hardness and numbered accordingly.

Minerals on moh’s scale of hardness are:TALC(1),GYPSUM(2),CALCITE(3),FLUORITE(4),APATITE(5),FELDSPAR(6),QUARTZ(7),TOPAZ(8),CORUNDUM(9) AND DIAMOND(10).

DENSITY:-MASS/VOLUME,DESCRIBED AS LOW, MEDIUM OR HIGH IF SPECIFIC GRAVITY IS LESS THAN 2.5,2.5 TO 3.5 OR MORE THAN 3.5 RESPECTIVELY.

PHYSICAL PROPERTIES OF MINERALS SPECIFIC GRAVITY:-specific gravity of a

mineral determines how heavy it is by its relative weight to water.

TRANSPARENCY:-TESTED ALONG THE THIN SHARP EDGES OF MINERAL KEEPING IT AGAINST A POWERFUL SOURCE OF LIGHT.

TYPICAL EXAMPLES OF MINERALS MUSCOVITE BAUXITE ASBESTOS TALC GYPSUM

MUSCOVITE FORM:-FLAKY,CRYSTALLINE

AND LAMELLAR COLOUR:-COLOURLESS STREAK:-WHITE LUSTRE:-PEARLY TO

VITREOUS CLEAVAGE:-PERFECT FRACTURE:-EVEN HARDNESS:-2.5-3 DENSITY:-MEDIUM SPECIFIC GRAVITY:2.8-2.9 DEGREE OF TRANSPARENCY:-

TRANSPARENT-TRANSLUCENT

BAUXITE FORM:-PISOTIEC AND

MASSIVE COLOUR:-BROWN AND

WHITE STREAK:-WHITE LUSTRE:-DULL OR

EARTHY CLEAVAGE:-ABSENT FRACTURE:-UNEVEN HARDNESS:-1-3 DENSITY:-LOW SPECIFIC GRAVITY:2-2.5 DEGREE OF

TRANSPARENCY:-OPAQUE

ASBESTOS FORM:-FIBROUS COLOUR:-PALE GREY STREAK:-WHITE LUSTRE:-SILKY CLEAVAGE:-PRESENT FRACTURE:-UNEVEN TO

HACKLY HARDNESS:-2-3 DENSITY:-MEDIUM SPECIFIC GRAVITY:-2.5 DEGREE OF

TRANSPARENCY:-OPAQUE

TALC FORM:-FOLIATED COLOUR:-GREY STREAK:-WHITE LUSTRE:-WAXY/PEARLY CLEAVAGE:-1 SET FRACTURE:-UNEVEN HARDNESS:-1 DENSITY:-MEDIUM SPECIFIC GRAVITY:-2.7-

2.8 DEGREE OF

TRANSPARENCY:-OPAQUE

GYPSUM FORM:-TABULAR COLOUR:-COLOURLESS STREAK:-WHITE LUSTRE:-VITREOUS AND

SILKY CLEAVAGE:-PERFECT FRACTURE:-EVEN TO

UNEVEN HARDNESS:-2 DENSITY:-LOW SPECIFIC GRAVITY:-2.3 DEGREE OF

TRANSPARENCY:-TRANSLUCENT TO TRANSPARENT

THANK YOU