Plan

Preparation (first hour)

• Mineral drawers will be assigned. A $25 deposit is requested. Most students will be paired up for a set of drawers. A few sets may have to be assigned to three students until week #3.
• A 45-minute video "The Physical Properties of Minerals" will be shown during the first part of the laboratory exercise.
• You will also be able to purchase a mineral identification kit, needed throughout the term. The accessories can also be bought individually (hand lens, porcelain plate, acid bottle, magnet).

Discover the basic physical properties commonly used to identify minerals by observing them in hand specimens from your set of mineral drawers. Some questions request that you compare a given mineral among different sets of drawers. (NOTE: avoid any specimen flagged with a paper slip... These will soon be replaced with better examples).
 

A) Identify your mineral among 40 others.
B) Describe systematically your mineral from a hand specimen.

Reference reading

Chapter 6 in Klein & Hurlbut (21st edition), or Chapter 5 (20th edition).

Material (provided unless indicated otherwise)

•  your own textbook (or a copy of Chapter 6)
•  hand specimens of 40 minerals
•  magnet, porcelain streak plate, bottles of dilute HCl and water, hand lens.

Requirements

• In Part I, refer to the specimens by their specimen, set and drawer number (e.g. #45-1-2 for mineral #45 from set #1, drawer #2). The specimen number is painted on the mineral. The set and drawer numbers appear on the front of each drawer.
• Hand in your report (on this form) to the teaching assistant by the end of our next practical exercise, on September 10.
• Late assignments or reports: a 5% penalty is assessed for each late day (max. extension: 5 days).

(IF YOU WANT TO HAND IN YOUR REPORT ON THIS FORM, YOU MAY WANT TO DELETE THE COVER PAGE BEFORE PRINTING IT...)
 

Introduction to Mineralogy 186-210A

Laboratory #1

Name/ID:

Part I. Introduction to the physical properties of minerals (1h00)

1. Optical properties (there may be more than one valid answer in some cases).

Select one mineral displaying each of these optical properties among the following specimens: sodalite (#4-1), hematite (#76-2), chalcocite (#96-2), talc (#15-1), stibnite (#79-2), labradorite (#13-1), fluorite (#60-2), sphalerite (#85-2), antigorite (#26-1).
 

metallic luster	resinous luster
vitreous luster	reddish brown streak
greasy luster	gray streak
silky luster	colourless streak
translucent	black streak
opaque	iridescent

Habit and/or colour can be very variable among specimens of a given mineral. Compare among different drawers several specimens of the following minerals: quartz (#9-1), fluorite (#60-2), hematite (#76-2), calcite (#52-2). Find examples where different specimens of the same mineral show:
 

...variable colour but same habit (describe briefly the habit and colour differences)

... same colour but variable habit (describe briefly the colour and habit differences)

...variable colour but similar streak (describe the streak and overall colour differences)

2. Solubility

Some minerals are very soluble (i.e. dissolve readily) in water or in acidic solutions. Examine chert (#10-1), dolomite (#53-2), aragonite (#54-2) and halite (#58-2) to find examples of:
 

... a mineral that dissolves in water

... a mineral that dissolves readily in dilute HCl but not perceptibly in water

... a mineral that dissolves somewhat in dilute HCl but not perceptibly in water

... a mineral that doesn't dissolve noticeably in water nor in dilute HCl

3. Mechanical properties

Find an example of each of the following properties among the following minerals: quartz (#9-1), garnet (#44-1), hornblende (#24-1), galena (#90-2), talc (#15-1), halite (#58-2), muscovite #16-1). There may be more than one valid answer for certain properties.

flexible and elastic	flexible but inelastic
prismatic cleavage	micaceous cleavage
cubic cleavage	conchoidal fracture

  Rank the six following minerals according to their relative hardness: rhodonite (#34-1), kaolinite (#28-1), garnet (#44-1), galena (#90-2), rhodochrosite (#51-2), topaz (#49-1). To do this, scratch the specimens with each other.

1st (hardest):	4th:
2nd:	5th:
3rd:	6th (softest):

4. Very few minerals display magnetism. Indicate below the formula for each mineral and mention whether or not magnetism is detectable.

pyrite (#81-2):	pyrrhotite (#98-2):
magnetite (#73-2):	hematite (#76-2):

5. Find an example of each of these growth habits among the following minerals: molybdenite (#84-1), stilbite (#6-1), cerussite (#55-2), antigorite (#26-1), actinolite (#23-1), smithsonite (#63-2), kyanite (#48-1), bauxite (#57-2), tourmaline (#42-1), glaucophane (#25-1).

bladed	prismatic
massive	fibrous/asbestiform
dendritic/arborescent	micaceous
Botryoidal	acicular
Earthy	sheaf-like

6. What is the difference between specific gravity and density?

Use the textbook to compare the specific gravity (G) of each pair of the following minerals and determine which one is the densest. Do a scratch test to figure out which one is the hardest. The difference in density can sometimes by felt by weighing two specimens in your hands.
 

mineral (check one)	Densest	Hardest
calcite (52-2, CaCO3) versus barite (100-3, BaSO4)
pyrolusite (64-2, MnO2) versus galena (90-2, PbS)
corundum (75-2, Al2O3) versus gypsum (104-3CaSO4• 2H2O)

Part II. Mineral identification from their properties (1h00).

A) Identify your mineral among the other 40, and indicate which characteristics you found most useful for their identification (e.g. an unusually high specific gravity, its conchoidal fracture, a reddish streak, a hardness higher than that of a steel blade).
 

Characteristic properties	Identification (name, formula, specimen number)

B) Describe the physical properties of the specimen identified above (e.g., colour, luster, streak, habit, cleavage, hardness, solubility in H₂O or HCl, brittleness vs. ductility, magnetism, unusual density, etc.) You may use the textbook but be selective. Textbook descriptions cover all the main varieties of a given mineral species. Use only the terms that apply to your specimen.