Lecture 40 Identification of minerals and rock samples

Lecture Series on Engineering Geology by Prof.Debasis Roy , Department of Civil Engineering IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in

Category:

Education

Tags:

• Identification
• of
• minerals
• and
• rock
• samples

[thealmightyX]

21:20 for ROCKS... skip past the mineral stuff...

[Golgotha357]

@AsphaltCowboy57

You can test anything on a streak plate. If you look at the properties of quartz or any other hard mineral you will see that they all have streak colors listed and they are all white usually. You may know what quartz is by looking at it but when you have a specimen that you cannot tell what it is it's best to do all tests on it and then check for possibilities. When you get into upper level classes it's not as easy to tell what things are by just one or two tests.

[THEMANIAC111]

i wander if anyone actually watched all of this.

[AsphaltCowboy57]

I thought that minerals with a hardness of 7 or more such as quartz were not to be used on porcelain streak plates as they were harder than the plate. The purpose of the streak plate is breakdown softer minerals into powder form. By scratching Quartz on the plate, he simply cut into the streak plate leaving powder porcelain behind. That also explains why both the clear and black colored quartz come up with a white streak color.

Am I right? I've got a test over this material soon.

[metfan89]

@mkongola perhaps but he obviously doesnt know much about what he is talking about. if are trying to say that pyroxene is a felsic mineral then you shouldnt be allowed to teach the subject

[ipodtouchmaster06]

@scrxbandit because he isnt stupid and learned english. Simple as that.

[mkongola]

@scrxbandit actually not because of what you are thinking but it is because this forum is international and in this era we are striving to think outside the box.

[mkongola]

I think it is appropriate to look at this type of professional presentation possitively and appreciate that thre is a great deal of work that this professor has carried out. I suggest you people comment the observation constructively so that if you happen to have similar opportunity of uploading your presentation(s) similar errors should be minimised. I have much respect to this Professor

[vidalmadjar]

2_2628872

Pumice is lighter in color (felsic), and scoria is darker. Also, pumice is denser (only 90% porosity)

[StoneTitan]

The obvious reason would be he planed to put it on the internet and for as many people as possible to get something out of his leasson