GUIA DE IDENTIFICACIÓN DE MINERALES
Lustre: metálico / submetálico / no metálico
Lustre Metálico Generalmente con raya de color, opacos
RAYA DUREZA COLOR REMARKS NOMBRE
S.G. 2.0
Steel GRAPHITE
Black 1 Basal cleavage; Soft, marks on paper, greasy feel.
gray GRAFITO
Used in lubricants and pencils.
S.G. 4.8
PYROLUSITE
Iron-black 1-2 Black Radiating fibers, granular masses, or dendritic; sooty.
PYROLUSITA
An ore of manganese.
S.G. 3.3 to 4.0
Yellow Your basic rust. Many forms and lusters. Occurs as
Yellow LIMONITE
1 to 5 brown to flattened crystals, massive, reniform, or stalactitic.
brown LIMONITA
black Common secondary mineral in rocks and soils.
An ore of iron.
S.G. 4.8 to 5.3
Many forms and lusters (can also occur in sub-
Red metallic to non-metallic forms). Can be massive,
Steel HEMATITE
brown to 1 to 6.5 radiating, botryoidal, and micaceous. The crystalline
gray HEMATITA
Indian red (metallic and sub-metallic) varieties are generally
harder than the earthy (non-metallic) varieties.
An ore of iron.
S.G. 7.6
Perfect cubic cleavage (3 @ 90°); Occurs in cubes;
Gray 2.5 Gray GALENA
may be massive or granular; heavy. The most
common ore of lead.
S.G. 10 to 12
Silvery
Hackly fracture, easily distinguished from galena by
Light gray white, SILVER
2.5 lack of cleavage. Malleable and ductile. Used in
to silver tarnishes PLATA
coinage, fillings for teeth, jewelry, silverplate,
to black
photography, wires.
S.G. 19.3
Pale to Hackly fracture. Malleable and ductile. Used in
GOLD
Yellow 2.5 to 3.0 golden coinage, fillings for teeth, jewelry, goldplate.
ORO
yellow Extensive use in computer industry as non-corrosive
contact points for silicon chips.
Bronze, S.G. 4.9 to 5.4
tarnishes Commonly called "peacock ore" because of the
Gray to BOURNITE
3.0 to dark purple shine when it tarnishes.
black BOURNITA
blue and A common source of copper.
purple
S.G. 8.5 to 9.0
Copper Copper Malleable and ductile. Used in coins, pipes, wires, KOPER
3.0
red red gutters, cooking utensils, pots and pans, jewelry, COBRE
decorative items.
Greenish- 4 Brass S.G. 4.3 CHALCOPYRITE
black yellow The distinctive buttery yellow color is often tarnished CALCOPIRITA
purple or gray; yellower and softer than pyrite.
An ore of copper.
S.G. 4.6
Distinctive chocolate brown streak. Commonly occurs
Black to as stratabound deposits in dunite segregations in CHROMITE
Chocolate
5.5 dark ultramafic rocks, and as podiform masses in
brown
brown serpentinite. Used in stainless steel, high CROMITA
temperature alloys, and as refractory bricks.
The ore of chromium.
S.G. 5.2
Conchoidal fracture. Strongly magnetic. Often called
MAGNETITE
Black 6 Black "lodestone." Common accessory mineral occurring as
MAGNETITA
disseminated grains in mafic igneous rocks.
An ore of iron.
S.G. 5.0
Often in cubic crystals. Can be massive, granular.
Black to Pale PYRITE
6 Common name: "Fool's gold." Commonly alters to
greenish brass PIRITA
limonite.
Sometimes mined as a source of sulfur.
LUSTRE: Sub metálico
RAYA DUREZA COLOR REMARKS NOMBRE
S.G. 3.3 to 4.0.
Your basic rust. Many forms and lusters. Occurs as
Yellow- Yellow to LIMONITE
1 to 5.5 flattened crystals, massive, reniform, or stalactitic.
brown dark brown LIMONITA
Common secondary mineral in rocks and soils.
An ore of iron.
S.G. 4.8 to 5.3
Many forms and lusters (can also occur in sub-metallic
Red
to non-metallic forms). Can be massive, radiating,
brown to Red, HEMATITE
1 to 6.5 botryoidal, and micaceous. The crystalline (metallic
Indian vermillion HEMATITA
and sub-metallic) varieties are generally harder than
red
the earthy (non-metallic) varieties.
An ore of iron.
LUSTRE: No-metálico. Raya incolora o de color muy claro
Dureza: 5.5
Dureza: 5.5 (se marca con un vidrio/navaja)
BREAKAGE SP.
HARD COLOR REMARKS NAME
PATTERN GR.
Crystals slender, fibrous. Often look like long,
2 directions, skinny rods. Commonly occur in cleavage
3.0 AMPHIBOLE
5.0 to good at Black to fragments or granular masses. Typical lusters;
to GROUP
6.0 approx. 60° green vitreous to dull. HORNBLENDE is a common
3.3 ANFIBOL
and 120° ferromagnesian mineral in intermediate
silicate rocks (granitic to dioritic composition).
In bladed aggregates. Cleavage parallel to
length of crystals. Hardness variable. Typical KYANITE
5.0 to Good in 1 Blue to
3.6 lusters: vitreous, pearly, dull. Used in the
7.0 direction green
manufacture of spark plugs and other high CIANITA
refractory porcelains.
Crystals "stubby" with nearly rectangular PYROXENE
2 directions,
3.1 cross section. Commonly in granular or GROUP
5.5 to poor to fair Green to
to crystalline masses. Typical lusters: vitreous to
6.0 at approx. black
3.5 dull. A common ferromagnesian mineral in
90° PIROXENO
mafic to ultramafic silicate rocks.
As cleavable masses or irregular grains in
Colorless, rocks; as crystals in pegmatites and some ORTHOCLASE
white, igneous bodies. Luster generally vitreous to FELDSPAR GROUP
2.5
2 directions, pink, red, pearly. Used in manufacture of some
6.0 to
good at 90° gray, porcelains. Orthoclase is the common
2.6 ORTOCLASA Gpo
green, feldspar found in felsic silicate rocks.
blue Common varieties include MICROCLINE FELDESPATO
(pink), and AMAZONITE (blue).
In cleavable masses or irregular grains.
Striations common on cleavage planes. Luster
generally vitreous to pearly. Used in PLAGIOCLASE
Colorless, FELDSPAR GROUP
2.6 manufacture of some ceramics. Forms a
2 directions, white,
6.0 to continuous series from the calcium rich variety
good at 86° gray to
2.8 to the sodium-rich variety (refer to Bowen's PLAGIOCLASA
black
Reaction Series). Plagioclase is the common Gpo.FELDESPATO
feldspar found in intermediate to mafic silicate
rocks.
Usually in 12 or 24 sided crystals (commonly
as porphyroblasts in schists): also massive. GARNET
Uneven Red to No cleavage, but some samples may exhibit
6.5 4.3
fracture brown parting. Typical lusters: resinous, vitreous,
dull. Used as an abrasive: well formed GRANATE
crystals may be used as gemstones.
Usually as disseminated grains in mafic
igneous rocks; as granular masses having
Olive OLIVINE
3.3 saccharoidal texture (looks like grains of
6.5 to Conchoidal green to
to sugar). Luster generally vitreous. Mined for
7.0 fracture yellow
3.4 refractory sand used in casting industry. A OLIVINO
green
common ferromagnesian mineral in mafic to
ultramafic silicate rocks.
As crystals with hexagonal cross section,
often with striations on prism faces. Also as
crystalline masses, granular aggregates,
Colorless
irregular grains, etc. Luster generally vitreous
or white QUARTZ
to greasy. Varieties include MILKY (white to
Conchoidal when
7.0 2.6 cloudy, usually due to included microscopic
fracture pure, but
air bubbles); SMOKEY (gray to black); ROSE CUARZO
may be
(pink); AMETHYST (violet). Used as a
any color
gemstone, to make glass, as a source of
silicon for the computer industry, a flux, a
filler, and an abrasive.
Translucent to opaque. Varieties include
AGATE (massive to banded, many colors); MICRO-
FLINT (dark gray to blue); CHERT (light- CRYSTALLINE
colored, white to gray); JASPER (commonly QUARTZ
Conchoidal Various
7.0 2.6 red but can include many hues); OPAL (milk-
fracture colors
white, yellow, green, red, multi hued with
"fire," waxy luster); CHALCEDONY (brown to CUARZO
gray, fibrous to botryoidal). Agate and opal MICROCRISTALINO
are used as gemstones.
Usually in trigonal prismatic crystals with
prominent lengthwise-running striations. TOURMALINE
Cleavage Varied;
7.0 to Typical lusters: vitreous to dull. Well-formed
not black 3.2
7.5 and colored crystals used as gemstones.
prominent common TURMALINA
Commonly occur in prgmatite dikes, and in
higher grade metamorphic rocks.
Cruciform twin crystals common; also
Red- elongate bladed crystals with rhombic cross STAUROLITE
Cleavage
7.0 to brown to sections. Luster resinous to vitreous when
not 3.7
7.5 brownish- unaltered; dull to earthy when altered or
prominent ESTAUROLITA
black impure. Well-formed, cross-shaped twins
used in jewelry ("Fairy Crosses").
Hexagonal, prismatic crystals. Luster BERYL
Imperfect Green to generally vitreous. Used as a source of
8.0 2.7
cleavage yellow beryllium for metal alloys. High quality crystals
used as gemstomes. BERILO
Colorless, Prismatic crystals, crystalline or granular TOPAZ
1 direction,
8.0 pink, 3.5 masses. Luster generally vitreous. High
poor quality crystals used as gemstone.
yellow TOPACIO
Crystals generally hexagonal prisms,
commonly barrel-shaped. Basal parting CORUNDUM
Parting, no Brown,
common. Typical lusters: vitreous to dull.
9.0 true pink, 4.0
Used as an abrasive; high quality, colored CORUNDO
cleavage ruby-red
crystals used as gemstones: RUBY (red), /CORINDON
SAPPHIRE (blue).
Uncut crystals have a characteristic greasy
Colorless, appearance; well-formed crystals are DIAMOND
10 4 directions pale 3.5 octahedral. Luster: adamantine. Industrial
yellow diamonds (borts) used as abrasives; high DIAMANTE
quality diamonds used as gemstones.
GRUPO DEL FELDESPATO
SERIE DE REACCIONES DE BOWEN