Quantcast

Latest Amphibole Stories

2008-05-14 03:00:23

By Lupulescu, Marian Readers may wonder why we need an article about amphiboles in this publication. There are considerable concerns about this topic, and I want to comment briefly about two of them. With some exceptions, many mineral lovers consider the amphibole-group minerals not spectacular enough to be collected and displayed; indeed, they believe these dark minerals are significant only for professional mineralogists who like to classify them in groups and species or for the...


Latest Amphibole Reference Libraries

28_9de5c05320ccdc491872fa501c117601
2005-05-26 12:19:41

Amphibole defines an important group of dark-colored rock-forming inosilicate minerals composed of double chain SiO4 tetrahedra linked at the vertices and generally containing ions of iron and/ or magnesium in their structures. In chemical composition and general characteristics they are very similar to the pyroxenes and, like them, fall into three series according to their system of crystallization. The chief difference between amphiboles and pyroxenes is in cleavage: amphiboles form oblique...

28_4724dc81fe2dc7af85b76d8cb74f2e4c
2005-05-25 11:51:11

Talc is a mineral composed of hydrated magnesium silicate with the chemical formula H2Mg3(SiO3)4 or Mg3Si4O10(OH)2. It occurs as foliated to fibrous masses, its monoclinic crystals being so rare as to be almost unknown. It has a perfect basal cleavage, the folia non-elastic although slightly flexible. It is sectile and very soft, with a hardness of 1 (Talc is the softest known solid). It has a specific gravity of 2.5 - 2.8, a waxlike or pearly luster, and is translucent to opaque. Its color...

More Articles (2 articles) »
Word of the Day
humgruffin
  • A terrible or repulsive person.
Regarding the etymology of 'humgruffin,' the OED says (rather unhelpfully) that it's a 'made-up word.' We might guess that 'hum' comes from 'humbug' or possibly 'hum' meaning 'a disagreeable smell,' while 'gruffin' could be a combination of 'gruff' and 'griffin.'