Zusammenfassung der Ressource
6.3 Minerals
- A mineral is a chemical
substance which is a
naturally occurring solid that
has not been made by
animal, plant or any other
type of organism.
- common minerals are
haematite, bauxite, galena,
malachite, chalcopyrite,
rutile, cassiterite,
chromite, pentlandite and
opal
- some minerals are
pure elements.eg.
silver and gold.
- native copper is found as pure
copper. more commonly, copper is
found as an ore. three copper ores
are bornite, azurite and malachite.
- Ores are rocks that
contain valuable
minerals like iron and
copper
- main properties of
minerals are their:
hardness, lustre, colour,
streak colour, flame
colour
- in flame tests, minerals are first ground
into powders or dissolved. some of the
poweres or dissolved mineral is then
put into a hot flame. the mineral glows
an gives the flame a charecteristic
colour that may then be used to
identify the mineral.
- hardness is assessed by
comparing minerals using Mohs
scale.
- colour is very useful when
prospecting for minerals. for
example, gold shows up as a
yellowish colour in rock and soil.
- lustre is how shiny a mineral is.
lustre is divided into many
categories. examples are glassy,
waxy, metallic, dull.
- streak is the colour left
behind when you try to
scratch and unglazed white
tile with the mineral.