Mineral Treasures:
Underground, minerals take hundreds of millions of years to form. Each with their own unique properties, minerals reveal the complexity of both physical and chemical processes that take place deep within the Earth. Throughout the ages, humans have been captivated by the beauty and mystery of how minerals have formed underground. Provided on this web page are many common minerals, but a few rare ones will be included as well. It is my hope that this web page will provide you with a "spark" of interest to participate in mineral collecting and identification. Click on the individual photos to enlarge for better quality viewing.
Amber (Fossilized Resin):
Mineral Class: Hydrocarbons
Chemical Name: Organic
Colors: yellow; sometimes brown to red
Streak: white
Luster: resinous
Mohs Scale of Hardness: 2 to 2.5
Formed: fossilized resin from extinct coniferous trees and insects
Crystal Form and Cleavage: amorphous (not truly a mineral)
Chemical Name: Organic
Colors: yellow; sometimes brown to red
Streak: white
Luster: resinous
Mohs Scale of Hardness: 2 to 2.5
Formed: fossilized resin from extinct coniferous trees and insects
Crystal Form and Cleavage: amorphous (not truly a mineral)
Amethyst Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: lilac to deep purple
Streak: white or clear
Luster: commonly vitreous (glassy)
Mohs Scale of Hardness: 7
Formed: in almost any type of rock
Crystal Form: prismatic
Photo: large Amethyst geode
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: lilac to deep purple
Streak: white or clear
Luster: commonly vitreous (glassy)
Mohs Scale of Hardness: 7
Formed: in almost any type of rock
Crystal Form: prismatic
Photo: large Amethyst geode
Cleavage or Fracture: irregular fracture
Ametrine Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: purple-violet and yellow
Streak: white or clear
Luster: greasy (translucent)
Mohs Scale of Hardness: 7
Formed: uneven heating deep underground
Crystal Form: commonly massive
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: purple-violet and yellow
Streak: white or clear
Luster: greasy (translucent)
Mohs Scale of Hardness: 7
Formed: uneven heating deep underground
Crystal Form: commonly massive
Cleavage or Fracture: irregular fracture
Aurichalcite:
Mineral Class: Carbonates
Chemical Name: Hydrous Calcium Carbonate
Colors: pale green-blue
Streak: white to pale green-blue shades
Luster: vitreous (glassy) to pearly
Mohs Scale of Hardness: 2 to 3
Formed: secondary, weather zone of copper-zinc ore deposits
Crystal Form: monoclinic to prismatic
Cleavage or Fracture: uneven fracture or fibrous
Transparency: transparent to translucent
Special Note: effervesces with HCL
Chemical Name: Hydrous Calcium Carbonate
Colors: pale green-blue
Streak: white to pale green-blue shades
Luster: vitreous (glassy) to pearly
Mohs Scale of Hardness: 2 to 3
Formed: secondary, weather zone of copper-zinc ore deposits
Crystal Form: monoclinic to prismatic
Cleavage or Fracture: uneven fracture or fibrous
Transparency: transparent to translucent
Special Note: effervesces with HCL
Azurite:
Mineral Class: Carbonates
Chemical Name: Hydrous Copper Carbonate
Colors: light to deep blue
Streak: light blue
Luster: vitreous (glassy), earthy to dull
Mohs Scale of Hardness: 3.5 to 4
Formed: forms with other copper ores
Crystal Form: prismatic or aggregates
Cleavage or Fracture: conchoidal fracture
Transparency: opaque, although translucent in thin splinters
Special Note: often occurs with Malachite, effervesces in HCL, and alters to Malachite.
Chemical Name: Hydrous Copper Carbonate
Colors: light to deep blue
Streak: light blue
Luster: vitreous (glassy), earthy to dull
Mohs Scale of Hardness: 3.5 to 4
Formed: forms with other copper ores
Crystal Form: prismatic or aggregates
Cleavage or Fracture: conchoidal fracture
Transparency: opaque, although translucent in thin splinters
Special Note: often occurs with Malachite, effervesces in HCL, and alters to Malachite.
Calcite with Twin Habit:
Mineral Class: Carbonates
Chemical Name: Calcium Carbonate
Colors: white or clear, tinged, blue, green, yellow, red, pink, brown
Streak: white or clear
Luster: vitreous (glassy) or greasy
Mohs Scale of Hardness: 3
Formed: very common mineral, especially in limestone and marble
Crystal Form: trigonal
Cleavage or Fracture: perfect cleavage
Special Note: effervesces with HCL
Chemical Name: Calcium Carbonate
Colors: white or clear, tinged, blue, green, yellow, red, pink, brown
Streak: white or clear
Luster: vitreous (glassy) or greasy
Mohs Scale of Hardness: 3
Formed: very common mineral, especially in limestone and marble
Crystal Form: trigonal
Cleavage or Fracture: perfect cleavage
Special Note: effervesces with HCL
Citrine Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: pale yellow to brown
Streak: white or clear
Luster: commonly vitreous (glassy)
Mohs Scale of Hardness: 7
Formed: more rare in its natural form
Crystal Form: prismatic
Photo: large prismatic crystals clustered together
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: pale yellow to brown
Streak: white or clear
Luster: commonly vitreous (glassy)
Mohs Scale of Hardness: 7
Formed: more rare in its natural form
Crystal Form: prismatic
Photo: large prismatic crystals clustered together
Cleavage or Fracture: irregular fracture
Fluorite:
Mineral Calss: Halides
Chemical Name: Calcium Fluoride
Colors: occurs in many colors, but purple and green are most common
Streak: white
Luster: vitreous (glassy)
Mohs Scale of Hardness: 4
Formed: often associated with lead and silver ores, hot springs, and pegmatite cavities
Crystal Form: cubic, octahedron, and massive
Transparency: transparent to translucent
Cleavage or Fracture: perfect octahedral cleavage and flat conchoidal fracture
Special Note: has fluorescence emissions with ultraviolet light
Chemical Name: Calcium Fluoride
Colors: occurs in many colors, but purple and green are most common
Streak: white
Luster: vitreous (glassy)
Mohs Scale of Hardness: 4
Formed: often associated with lead and silver ores, hot springs, and pegmatite cavities
Crystal Form: cubic, octahedron, and massive
Transparency: transparent to translucent
Cleavage or Fracture: perfect octahedral cleavage and flat conchoidal fracture
Special Note: has fluorescence emissions with ultraviolet light
Galena:
Mineral Class: Sulfides
Chemical Name: Lead Sulfide
Colors: bright silver to tarnished and dull-lead gray
Streak: lead-gray to black
Luster: shiny metallic to dull metallic
Mohs Scale of Hardness: 2.5+
Formed: can be formed all three major rock types
Crystal Form: cubic, pyritohedron, massive
Photo: pyritohedron crystals interconnecting
Cleavage or Fracture: perfect cleavage
Chemical Name: Lead Sulfide
Colors: bright silver to tarnished and dull-lead gray
Streak: lead-gray to black
Luster: shiny metallic to dull metallic
Mohs Scale of Hardness: 2.5+
Formed: can be formed all three major rock types
Crystal Form: cubic, pyritohedron, massive
Photo: pyritohedron crystals interconnecting
Cleavage or Fracture: perfect cleavage
Goethite:
Mineral Class: Oxides
Chemical Name: Iron Hydroxides
Colors: variety of colors: orange-to black-brown
Streak: brown-yellow to ochre-red
Luster: shiny or dull metallic or iridescent with multicolored appearance
Mohs Scale of Hardness: 5 to 5.5
Formed: in oxidation zones within veins
Crystal Form: orthorhombic
Special Note: often found as botryoidal masses
Photo: This one has more of the iron components that give it the ochre-red color.
Chemical Name: Iron Hydroxides
Colors: variety of colors: orange-to black-brown
Streak: brown-yellow to ochre-red
Luster: shiny or dull metallic or iridescent with multicolored appearance
Mohs Scale of Hardness: 5 to 5.5
Formed: in oxidation zones within veins
Crystal Form: orthorhombic
Special Note: often found as botryoidal masses
Photo: This one has more of the iron components that give it the ochre-red color.
Gold Nugget:
Mineral Class: Native Elements
Chemical Name: Gold
Colors: gold
Streak: golden-yellow
Luster: Metallic
Mohs Scale of Hardness: 2.5 to 3
Formed: in igneous rock or riverbed gravel
Cleavage or Fracture: irregular fracture
Transparency: opaque
Special Note: malleable when heated
Chemical Name: Gold
Colors: gold
Streak: golden-yellow
Luster: Metallic
Mohs Scale of Hardness: 2.5 to 3
Formed: in igneous rock or riverbed gravel
Cleavage or Fracture: irregular fracture
Transparency: opaque
Special Note: malleable when heated
Hematite:
Mineral Class: Oxides
Chemical Name: Iron Oxide
Colors: gray to black and red to brown
Streak: red to rusty brown
Luster: shiny to dull metallic
Mohs Scale of Hardness: 6.5
Formed: in many types of rocks
Cleavage or Fracture: conchoidal fracture
Transparency: translucent to opaque
Special Note: lacks strong magnetism
Chemical Name: Iron Oxide
Colors: gray to black and red to brown
Streak: red to rusty brown
Luster: shiny to dull metallic
Mohs Scale of Hardness: 6.5
Formed: in many types of rocks
Cleavage or Fracture: conchoidal fracture
Transparency: translucent to opaque
Special Note: lacks strong magnetism
Labradorite:
Mineral Class: Silicates
Chemical Name: Sodium Calcium Aluminum Silicate
Colors: blue, gray, and white
Streak: white
Luster: vitreous to pearly on cleavages
Mohs Scale of Hardness: 6 to 6.5
Crystal Form: triclinic, usually massive
Cleavage: perfect cleavage
Fracture: uneven to conchoidal fracture
Transparency: transparent to translucent
Special Note: Labradorite is a Feldspar mineral, twinning is common
Chemical Name: Sodium Calcium Aluminum Silicate
Colors: blue, gray, and white
Streak: white
Luster: vitreous to pearly on cleavages
Mohs Scale of Hardness: 6 to 6.5
Crystal Form: triclinic, usually massive
Cleavage: perfect cleavage
Fracture: uneven to conchoidal fracture
Transparency: transparent to translucent
Special Note: Labradorite is a Feldspar mineral, twinning is common
Magnetite:
Mineral Class: Oxides
Chemical Name: Iron Oxide
Colors: black, gray, and dark red
Streak: black
Luster: dull metallic
Mohs Scale of Hardness: 5.5 to 6.5
Formed: in many types of rocks
Crystal Form: octahedron
Special Property: strongly magnetic
Cleavage or Fracture: irregular fracture
Transaprency: opaque
Chemical Name: Iron Oxide
Colors: black, gray, and dark red
Streak: black
Luster: dull metallic
Mohs Scale of Hardness: 5.5 to 6.5
Formed: in many types of rocks
Crystal Form: octahedron
Special Property: strongly magnetic
Cleavage or Fracture: irregular fracture
Transaprency: opaque
Malachite:
Mineral Class: Carbonates
Chemical Name: Hydrous Copper Carbonate
Colors: light to dark green
Streak: pale green
Luster: vitreous (glassy), silky, earthy to dull
Mohs Scale of Hardness: 3.5 to 4
Formed: found with other copper ore deposits, especially Azurite
Crystal Form: massive, botryoidal, acicular to tabular prismatic
Cleavage or Fracture: subconchoidal to irregular fracture
Transparency: translucent to opaque
Chemical Name: Hydrous Copper Carbonate
Colors: light to dark green
Streak: pale green
Luster: vitreous (glassy), silky, earthy to dull
Mohs Scale of Hardness: 3.5 to 4
Formed: found with other copper ore deposits, especially Azurite
Crystal Form: massive, botryoidal, acicular to tabular prismatic
Cleavage or Fracture: subconchoidal to irregular fracture
Transparency: translucent to opaque
Milky Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: cloudy white
Streak: white or clear
Luster: greasy
Mohs Scale of Hardness: 7
Formed: in almost any type of rock
Crystal Form: prismatic
Photo: small translucent crystals
Note: sometimes called Snow Quartz
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: cloudy white
Streak: white or clear
Luster: greasy
Mohs Scale of Hardness: 7
Formed: in almost any type of rock
Crystal Form: prismatic
Photo: small translucent crystals
Note: sometimes called Snow Quartz
Cleavage or Fracture: irregular fracture
Opal:
Mineral Class: Silicates
Chemical Name: Hydrous Silicon Dioxide
Colors: pale, shimmers with many colors
Streak: white
Luster: sometimes vitreous, but mostly pearly
Mohs Scale of Hardness: 5.5 to 6.5
Formed: silica carried into rock cracks by water, then dried
Crystal Form: amorphous (not truly a mineral)
Cleavage or Fracture: irregular but sometimes conchoidal
Transparency: transparent and opaque
Chemical Name: Hydrous Silicon Dioxide
Colors: pale, shimmers with many colors
Streak: white
Luster: sometimes vitreous, but mostly pearly
Mohs Scale of Hardness: 5.5 to 6.5
Formed: silica carried into rock cracks by water, then dried
Crystal Form: amorphous (not truly a mineral)
Cleavage or Fracture: irregular but sometimes conchoidal
Transparency: transparent and opaque
Pyrite (Fool's Gold):
Mineral Class: Sulfides
Chemical Name: Iron Sulfide
Colors: brass yellow, sometimes tarnished to dull brass
Streak: green-black to brown-black
Luster: shiny metallic to dull metallic
Mohs Scale of Hardness: 6 to 6.5
Formed: can be found in all three major rock types
Crystal Form: pyritohedron, cubic, and massive
Photo: pyritohedron crystals connecting one another
Cleavage or Fracture: conchoidal fracture
Photo: four pyrite crystals in the cubic form
Special Note: crystals grew together interlocking with each other
Chemical Name: Iron Sulfide
Colors: brass yellow, sometimes tarnished to dull brass
Streak: green-black to brown-black
Luster: shiny metallic to dull metallic
Mohs Scale of Hardness: 6 to 6.5
Formed: can be found in all three major rock types
Crystal Form: pyritohedron, cubic, and massive
Photo: pyritohedron crystals connecting one another
Cleavage or Fracture: conchoidal fracture
Photo: four pyrite crystals in the cubic form
Special Note: crystals grew together interlocking with each other
Red Calcite:
Mineral Class: Carbonates
Chemical Name: Calcium Carbonate
Colors: red to red-brown
Streak: white or clear
Luster: vitreous (glassy) and greasy
Mohs Scale of Hardness: 3
Formed: common in sedimentary and metamorphic rocks
Crystal Form: prismatic (12-sided) or massive
Photo: clusters of individual red calcite crystals
Chemical Name: Calcium Carbonate
Colors: red to red-brown
Streak: white or clear
Luster: vitreous (glassy) and greasy
Mohs Scale of Hardness: 3
Formed: common in sedimentary and metamorphic rocks
Crystal Form: prismatic (12-sided) or massive
Photo: clusters of individual red calcite crystals
Rock Crystal Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: colorless
Streak: white or clear
Luster: vitreous (glassy)
Mohs Scale of Hardness: 7
Formed: in almost any type of rock
Crystal Form: prismatic
Photo: large transparent crystals
Special Note: sometimes called "frozen ice"
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: colorless
Streak: white or clear
Luster: vitreous (glassy)
Mohs Scale of Hardness: 7
Formed: in almost any type of rock
Crystal Form: prismatic
Photo: large transparent crystals
Special Note: sometimes called "frozen ice"
Cleavage or Fracture: irregular fracture
Rose Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: light pink
Streak: white or clear
Luster: vitreous (glassy), commonly greasy or milky
Mohs Scale of Hardness: 7
Colored by: in almost any type of rock
Formed: in almost any type of rock
Crystal Form: prismatic (less common) to massive (most common)
Photo: clusters of prismatic crystals
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: light pink
Streak: white or clear
Luster: vitreous (glassy), commonly greasy or milky
Mohs Scale of Hardness: 7
Colored by: in almost any type of rock
Formed: in almost any type of rock
Crystal Form: prismatic (less common) to massive (most common)
Photo: clusters of prismatic crystals
Cleavage or Fracture: irregular fracture
Smoky Quartz:
Mineral Class: Silicates
Chemical Name: Silicon Dioxide (silica)
Colors: black, brown, to yellow-brown
Streak: white or clear
Luster: commonly vitreous (glassy)
Mohs Scale of Hardness: 7
Colored by: natural radiation of the Earth
Formed: often found in granite
Crystal Form: prismatic
Photo: two crystals intersecting at right angles
Cleavage or Fracture: irregular fracture
Chemical Name: Silicon Dioxide (silica)
Colors: black, brown, to yellow-brown
Streak: white or clear
Luster: commonly vitreous (glassy)
Mohs Scale of Hardness: 7
Colored by: natural radiation of the Earth
Formed: often found in granite
Crystal Form: prismatic
Photo: two crystals intersecting at right angles
Cleavage or Fracture: irregular fracture
The Far River:
The awe-inspiring space music of John Serrie creates a sense of curiosity, wonder, and relaxation. One particular CD of John Serrie's titled "And The Stars Go With You " features a 10-minute track called " The Far River". The music for this track gives an atmospheric sense or feeling of traveling in space combined with underground exploration. Enjoy!
