Lecture 9 Flashcards
Which mineral group is dominant on earth?
Silicates
What are the mineral groups?
Native elements Sulfides and sulfosalts Halides Oxides and Hydroxides Carbonates Silicates
What are the native elements (Pure elements)
Free uncombined elements (1 single element)
What is characteristic of metals (native elements)
Dense, soft, opaque, malleable, ductile. Good elecricity conductors. Massive, dendritic, wire like
What is characteristic of semi metals (native elements)
Poor electricity conductors, commonly only occur in nodular masses
What is characteristic of the nonmetals? (Native elements)
Transparent to translucent- do not conduct electricity. Have the trend to form distinct, often large sized crystals.
What are some examples of metals?
Gold, Silver and Platinum (occur frequently together)
What are some examples of semimetals?
Arsenic and Antimony
What are some examples of nonmetals?
Sulphur and carbon
What are sulfides?
Minerals formed by a metallic element and sulphur. Can be replaced by tellurium and arsenic as well
What lustre do the sulfides often present?
Metallic (eg: Galena)
Are sulfides dense or not dense?
Dense (Galena, molybendite etc)
What sulfides are nonmetallic?
Orpiment and realgar (both are toxic, made with arsenic)
What are sulfosalts?
Mixed sulfides in which a semimetallic element is presented with a metallic one
What is Pyrite?
The most frequent sulfide in nature. “Fools Gold”. Cubical mineral, can create a rare pentagon shape
What is an example of some sulfosalts?
Stephanite, Pyrargyrite (similar composition of silver, antimone, and sulphur-different valences creates different appearances)
What are oxides?
Compounds formed from various metallic elements and oxygen-oxygen plays the role of an anion. (gives away an electron)
What are some properties of oxides?
High variability of habit and colour, flexible crystal structures which accept lots of impurities. Occur in all 3 rock domains
What are some examples of oxides?
Uraninite, Magnetite, Ilmenite, Rutile, Corundum, Sapphire, Ruby, Hydroxides
What special property does magnetite have?
It’s magnetic lmao
What do ruby and sapphire demonstrate?
How flexible carbon is
What are carbonates?
Minerals that contain CO3
What is the most common carbonate?
Calcite
What are some of the characteristics of carbonates?
Usually present as well developed, rhombohedral crystals and bright colours. All 3 rock domains, most commonly sedimentary
What are aragonites (carbonates)?
Unstable carbonate-recrystallizes after organism death into calcite
What are some examples of carbonates?
Calcite, aragonite, baritocalcite, dolomite (mixed calcium and magnesium)
What are sulfates?
Minerals in which metallic elements are combined with radicals SO4.
Which rock domain do the sulfates mostly occur in?
Sedimentary
What is the most common sulfate?
Gypsum
What are some of the properties of sulfate?
Soft, light minerals, present in pale colours.
What are some examples of sulfates?
Gypsum, Anhydrite
