Thursday, January 1, 2009

Nominated one of the 100 Best Blogs for Earth Science Scholars

By: by Bachelors Degree Online

Thanks & Happy New Year!

Oscar G. Shelly

Extinct minerals: Brazilianite...due to mineralogists? or Ice....due to global warming?

Brazilianite

I read something today (1/1/2009), - Happy New Year by the way - that caught my eye, and it was related to minerals extinction. The article / blog made me wonder if in fact minerals are subject to extinction due to Geological causes, according to Andrew's Geology blog. After serious, and some not so serious thinking, I came up to the following conclusions / examples that I put into consideration for comments / critics.

I believe that is true that some minerals are subject to extinction, due to a variety of causes / phenomena. The first one that comes to mind is the mineral ice. If after all, Al Gore is right with his Global Warming theory, this will be the cause for melting icebergs, glaciers, and the poles in general, which will make ice disappear from the Earth, or better yet: follow one of Newton's laws; thus, ice will be transformed into water and/or vapor. What about snow?

Now, another one that comes to mind is the Brazilianite. A beautiful mineral with a beautiful name too in honor of its country in which it was discovered Brazil. Why does this mineral being so much harder, and stable than ice would disappear from the Earth? well, the disappearance will not be from the Earth, but from the pegmatites of Brazil (at least the ones so far discovered and exploited); Brazilianite specimens have been placed into many Museus and mineralogical collections around the globe, including mine. This is a mineral you don't see anymore in trade shows, so as far as I am concerned, there is another cause for mineral extinction: Avid mineralogists.

Let me take advantage of discussing about this amazing mineral sadly extinct to talk about its mineralogical features as follows:

Chemical Formula: NaAl3(PO4)2(OH)4
Composition: Molecular Weight = 361.91 gm
Sodium 6.35 % Na 8.56 % Na2O
Aluminum 22.37 % Al 42.26 % Al2O3
Phosphorus 17.12 % P 39.22 % P2O5
Hydrogen 1.11 % H 9.96 % H2O
Oxygen 53.05 % O

Name Origin: Named after its first discovery in Brazil.
Crystal System: Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 21/n
Cleavage: [010] Good
Color: Colorless, Greenish yellow, Yellow green, Light yellow.
Density: 2.98
Diaphaniety: Transparent
Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Habit: Spherical - Spherical, rounded aggregates.
Hardness: 5.5 - Knife Blade
Luster: Vitreous (Glassy)
Streak: White
Radioactivity: Brazilianite is not Radioactive

Saturday, December 13, 2008

Is snow a mineral? Of quartz! just kidding, it's made out of one mineral: ICE



I haven't have the opportunity of collecting a snow flake to analyze it under the microscope, or simply with a magnifying glass just to make sure I too believe that snow is made out of ice crystals, and that these are considered just like any other specimen, a true mineral! unbelievable uh? Anyhow, this is the hyperlink to a website in which I saw the latest and most astonishing pictures of snow crytals I've ever seen: Snowflakes
.

If someone asked me what is that I learned in the subject of mineralogy about ice as a mineral I can still remember that it has basal cleveage, and therfore, that permits the flow of ice in a glaciar. Is it true? does it make sense? I leave this open for discussion.

Following is the technical data of ice crystals:

Chemical Formula: H2O

Composition: Molecular Weight = 18.02 gm
Hydrogen 11.19 % H 100.00 % H2O
Oxygen 88.81 % O

Environment: Cold weather as snow crystals, coating ponds, glaciers, and icebergs.
Locality: World wide (I don't think someone has ever seen snow in the Sahara Desert though).
Name Origin: From the Middle English "is" or "iis", related to the Dutch "ijs" and German "eis".

Cleavage: None according to many, but it does have basal cleavage
Color: Colorless, Pale blue, Greenish blue, White.
Density: 0.9167
Diaphaniety: Transparent
Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Habit: Crystalline - Coarse - Occurs as well-formed coarse sized crystals.
Habit: Dendritic - Branching "tree-like" growths of great complexity (e.g. pyrolusite).
Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Hardness: 2.5 - Finger Nail
Streak: White
Luminescence: Non-fluorescent.
Luster: Vitreous - Dull