martes, 19 de mayo de 2009

Characteristics of Minerals













Color
Minerals have a huge viarity of colors, blue, red green, orange, yellow and even colorless. Even though their beautiful colors, it is not good to identify minerals by their color because many minerals can have that same color. In this picture you can see many colorful minerals.












Streak






The streak is the powder a mineral lefts when it is scratch. Scientists can use the color of the streak to identify a mineral but it is really hard. Many minerals have the color of its streak like pyrite but many others have a different color in their streak like Cinnabar.









Luster






Luster describes how light is reflected in a mineral. There are nine types of lusters, these are, earthy, waxy, pearly, glassy, metallic, greasy, dull or submetallic and silky. For example, quartz has a glassy luster, galena has a metallic luster, graphite has a greasy luster, gypsum alabaster has a waxy luster, talc has a dull or submetallic luster.






Density






Density means mass divided by volume. The size doesnt matter because some smaller minerals are denser that some that are bigger. Dense is a good way to identify a mineral because each mineral has its own density. Galena is a very dense mineral, it has a density of 7.4g/ccm.






Hardness





Hardness is the ability of a mineral to resist being scratched. There are the diferent steps to measure hardness in the Mohs scale, diamond is the hardest.
Mohs hardness
Mineral
1
Talc (Mg3Si4O10(OH)2)
2
Gypsum (CaSO4·2H2O)
3
Calcite (CaCO3)
4
Fluorite (CaF2)
5
Apatite (Ca5(PO4)3(OH-,Cl-,F-)
6
Feldspar (KAlSi3O8)
7
Quartz (SiO2)
8
Topaz (Al2SiO4(OH-,F-)2)
9
Corundum (Al2O3)
10
Diamond (C)

Crystal System





The crystal system of a mineral is the structure formed given by the number of sides and the angles in a crystal. There are six types of crystal systems, isometric or cubic, tetragonal, hexagonal, orthorombic, monoclinic and triclinic. Halite has a cubic or isometric crystal system.




Cleavage or Fracture


Fracture is the formed left when a mineral splits irregulary. Cleavage is when a mineral can split into flat surfaces. this is because of its atoms. For example Mica has cleavage and





miƩrcoles, 13 de mayo de 2009

Introduction



My name is Diego Herrera and I have been assigned a project in my science class. I was assigned Minerals so I have to tell you all about minerals. The characteristics of many kinds of minerals, their luster, the color, their cleavage or fracture, their streak and the hardness and field test. I hope you like my science blog.


Science Project Proposal Summary

Roll: My roll is going to be to show people many minerals and their properties. I will write about minerals like quartz, calcite and other common and not common minerals. The program I ‘m going to use is PowerPoint to make slides with the characteristics of each mineral.
Goal: My goal is to make a good study guide for the minerals unit test. This study guide will be easier to study and very organized. I will get a good grade in the mineral unit test with this very good study guide.
Audience: The audience is going to be students that are going to take this mineral exam. This study guide will help them to memorize the main mineral’s names and give them strategies to find mineral characteristics.
Situation: The situation is that a very important mineral unit exam is coming and I need a study guide to memorize the minerals and its characteristics, This will help me to get a successful grade in this exam and rise my science grade.
Products: To make this study guide I will need my science notes, the Internet to find new things about minerals and PowerPoint to make the mineral slide show and study guide.