Cerrar
Has 2 planes at 90 degrees. Crystals are prismatic (blocky). It can be dark green, brown or black, and vitreous (glassy). Streak is greenish white. This is a mafic mineral.
Crystals are acicular (elongated) like needles. It can be dark green, brown or black, and vitreous (glassy). Streak is dark green. This is a magic mineral.
One cleavage plane. Usually in plastic like sheet forms but one is massive and can be slippery. Can come in the colour green or simply be dark vs light sheets. One is a mafic mineral.
Is transparent to translucent. White to colourless but can also have shades of other colours. It is vitreous (glassy). It is lightweight and soft (scratch with a knife). It is prismatic.
Is soft (can scratch with a knife). It is similar to calcite but is generally cubic. Vitreous and can clear to white with other colour contaminants.
It is hard, cannot be scratched with a knife. Can be various colours, cloudy white, pink, etc. Has no cleavage.
Hard, heavy. Is transparent to opaque. Most commonly red, reddish brown. Is vitreous and prismatic. Streak is white (colourless).
Is VERY soft (scratch with finger). Appears similar to halite but is cloudy. Usually whit, vitreous to pearl. Can have shades of yellow, red or brown. Feels warm compared to quartz.
GREEN. Heavy. Is hard and vitreous. This is a mafic mineral.
Is hard, can have a prismatic shape. Can come in pink, orange and red.
Is light in colour, hard and usually translucent to opaque. It is usually grey, white or colourless. This is a mafic mineral.
GOLD! with a metallic lustre. Hard and has a brassy yellow colour. Forms nice prismatic shapes e.g. cubes, pentagonal faces, etc.
Gold. Soft, very goldish-yellow. May have purple areas and has a prismatic crystal habit
Is soft, heavy and grey to silver grey in colour. It is metallic and prismatic forming shapes such as cubes.
Is soft, light and opaque. Is metallic to earthy and silver-black in colour. Has lumps and scales.
Can be found in various colours such as red, orange and brown. It can also be steel like coming in silver-grey to black. The streak is red to brownish red. It is metallic or can be earthy.
Heavy. Can be black, brown, yellow, reddish, green, white or colourless. Streak is always lighter coloured than specimen so yellow to light brown. It can be sub-metalic and shiny.
YELLOW. Soft, light weight.
Porphyritic (coarse phenocrysts in a fine-grained matrix). Volcanic equivalent of diorite. Is usually grey with pyroxene and plagioclase phenocrysts.
This is a mafic rock. It is usually aphanitic (all fine grained) but can also be porphyritic (fine with coarse phenocrysts). It is dark grey to black in colour and may have a few vesicles. There may also be specks of olivine, pyroxene or plagioclase.
Porphrytic with needle shaped feldspar or hornblende phenocrysts. The rock is grey-whitish. Main mineral component is plagioclase.
Phaneritic (all coarse grained), is distinctively black and white like salt and pepper. It is made up of mainly plagioclase and either amphibole or pyroxene.
Phaneritic, dark mafic rock. It is the plutonic equivalent to basalt, it is dark grey to black. Main components are plagioclase and pyroxene with less olivine.
Phaneritic felsic rock. It is usually light coloured containing pink or white feldspar. It also has scattered dark phenocryts
Phaneritic olivine rich rock. Often contains chromite or magnetite which come across as little black specks.
Usually aphanitic, light coloured and glassy. Has several varieties such as pumice (very light and sponge like) and obsidian (layers of black phenocryts).
Hard, dark coloured rock. Looks like a hard mudstone with no clasts and has a matte sheen.
