MOCK BOARD EXAM DAY 2, SERIES 1

Limonite

It is an amorphous mineral that occur in compact, smooth, rounded masses or in soft earthy masses. No cleavage, it has a hardness of 5.5; sp. gr. 3.5 to 4.0; rusty or blackish color and earthy luster gives yellow brown streak.

Granite

Coarse-grained igneous rock consisting essentially of quartz (20-40%), alkali feldspar and very common mica (biotite or muscovite), accessory mineral maybe present including sparite, zricon and magnesite.

Marine environment below CCD

Thich chert deposits are usually formed in?

Calcite compensation depth

also known as CCD, is the depth in the oceans below which the rate of supply of calcite (calcium carbonate) lags behind the rate of solvation, such that no calcite is preserved.

Cobaltinitrite

The stain used to identify feldspar.

Allochems

Calcium carbonate grains that are transported and deposited as clasts.

Sparite

A coarse grained (>0.01mm) crystalline calcite cement, formed after deposition.

Micrite

limestone composed of very tiny calcite particles - solidified lime mud.

Allochems

The following comprise carbonate rocks except:

-Sparite

-Micrite

-Allochems

-Biolithic elements

Protolith

the original rock from which a metamorphic rock formed.

capillary or filiform

crystal habit in which the crystals occur as hairlike or threadlike. (e.g. zeolites)

Acicular

crystal habit in which the crystals occur as needlelike. (e.g. Natrolite, Rutile)

Drusy

or encrustation, crystal habits where the surface is covered with a layer of small crystals. (e.g. Uvarovite, Malachite, Azurite, Quartz)

Bladed

Crystal habit where it forms aggregates of thin lath-like crystals (e.g. kyanite, Actinolite).

Amygdaloidal

crystal habit where the vesicles are completely or partially filled with secondary minerals. (e.g. Heulandite)

Botryoidal

also known as globular, this crystal habit have the form of a bunch of grapes. (e.g. Hematite, Pyrite, Malachite, Smithsonite, Hemimorphite, Adamite, Variscite)

Columnar

crystal habit where it is similar to fibrous: Long, slender prisms often with parallel growth. (e.g. Calcite, Gypsum/Selenite).

Coxcomb

crystal habit where the aggregates are flaky or tabular crystals are closely spaced. (e.g. Barite, Marcasite)

Cubic

crystal habit where crystals are cubic (e.g. Pyrite, Galena, Halite)

Dendritic

or arborescent, crystal habit where crystal are treelike or branches of a tree branching in one or more direction from central point. (e.g. Romanechite and other Mn-oxide minerals, magnesite, native copper)

Dodecahedral

crystal habit where it is Rhombic dodecahedron, 12-sided, six planes of cleavage. (e.g. Garnet)

Enantiomorphic

crystal habit where it has Mirror-image habit (i.e. crystal twinning) and optical characteristics; right- and left-handed crystals. (e.g. Quartz, Plagioclase, Staurolite)

Equant

or stout, crystal habit is roughly equal in all dimensions. (e.g Olivine, Garnet)

Fibrous

crystal habit gives extremely slender prisms. (e.g. Serpentine group, Tremolite (i.e. Asbestos))

lamellar

also Foliated or micaceous, crystal habit forms layered structure, parting into thin sheets (e.g. Mica (Muscovite, Biotite, etc.))

Granular

crystal habit where aggregates of anhedral crystals in matrix. (e.g. Bornite, Scheelite)

anhedral

term for no crystal faces.

Hemimorphic

crystal habit where it has doubly terminated crystal with two differently shaped ends. (e.g. Hemimorphite, Elbaite)

Hexagonal

crystal habit has a hexagon shape, six-sided. (e.g. Quartz, Hanksite)

Hopper crystals

crystal habit are like cubic, but outer portions of cubes grow faster than inner portions, creating a concavity. (e.g. Halite, Calcite, synthetic Bismuth)

Mammillary

crystal habit are breast-like: surface formed by intersecting partial spherical shapes, larger version of botryoidal, also concentric layered aggregates. (e.g. Malachite, Hematite)

Massive

or compact, crystal habit has no shape or shapeless, no distinctive external crystal shape. (e.g. Limonite, Turquoise, Cinnabar, Realgar)

Nodular

or tuberose, crystal habit are deposit of roughly spherical form with irregular protuberances. (e.g. Chalcedony, various Geodes)

Octahedral

crystal habit is an octahedron, eight-sided (two pyramids base to base). (e.g. Diamond, Magnetite)

Platy

Crystal habit is flat, tablet-shaped, prominent pinnacoid. (e.g. Wulfenite)

Plumose

Crystal habit that are fine scales with divergent or featherlike structure. (e.g. Aurichalcite, Boulangerite, Mottramite)

Prismatic

crystal habit is elongate, prism-like: well-developed crystal faces parallel to the vertical axis. (e.g. Tourmaline, Beryl)

Pseudo-hexagonal

crystal habit shows a hexagonal appearance due to cyclic twinning. (e.g. Aragonite, Chrysoberyl)

Radiating

or divergent, crystal habit radiating outward from a central point. (e.g. Wavellite, Pyrite suns)

Reniform

or colloform, crystal habit similar to botryoidal/mamillary: intersecting kidney-shaped masses. (e.g. Hematite, Pyrolusite, Greenockite)

Reticulated

crystal habit have crystals forming net-like intergrowths. (e.g. Cerussite)

Rosette

or lenticular (lens shaped crystals), crystal habit are platy, radiating rose-like aggregate. (e.g. Gypsum, Barite (i.e. Desert rose))

Sphenoid

crystal habit is wedge-shaped. (e.g. Sphene)

Stalactitic

crystal habit forms as stalactites or stalagmites; cylindrical or cone-shaped. (e.g. Calcite, Goethite, Malachite)

Stellate

crystal habit is star-like, radiating. (e.g. Pyrophyllite, Aragonite)

Striated

Not a habit per se, but a condition of lines that can grow on certain crystal faces on certain minerals. (e.g. Tourmaline, Pyrite, Quartz, Feldspar, Sphalerite)

tabular

also termed stubby or blocky, crystal habit is more elongated than equant, slightly longer than wide, flat tablet shaped. (e.g. Feldspar, Topaz)

Tetrahedral

Tetrahedra-shaped crystals, pyramid like. (e.g. Tetrahedrite, Spinel, Magnetite)

Wheat sheaf

crystal habit that are like bundle shaped aggregates resembling wheat sheafs after hand reaping wheat. (e.g. Stilbite)

Hardness

The resistance that a mineral offers to breaking, crushing, bending or tearing is called?

Riecke's principle

Principle where the solution takes place at points of greatest pressure in a crystal, with concurrent precipitation at the area of least pressure.

Ultrabasic

Igneous rock having less than 45% silica content are classified as:

-Acidic

-Basic

-Ultrabasic

-Intermediate

45 degrees

positioned degree where the optic sign of a biaxial mineral is conveniently determined with the mineral.

Index of Refraction

An optical property determined in thin section by the Becke Line test.

Becke line

A bright halo that is observed near the border of a particle immersed in a liquid of a different refractive index.

Birefringence

the optical property of a material having a refractive index that depends on the polarization and propagation direction of light.

Sphalerite

Black Jack refers to what mineral?

True

True or False: The Wentworth scale is only used to classify clastic sedimentary rocks.

Udden-Wentworth scale

the classification of sediments by size; a boulder is the largest grain size and clay is the smallest grain size in this classification system.

Websterite

Plutonic type of rock, composed of 75% clinoproxene and 25% orthopyroxene.

Plagioclase Feldspar

Sodium-calcium aluminosilicate group that range from the calcium-rich Anorthite to the sodium-rich Albite. Usually has striations on it.

Rhyolite

Volcanic rock made up of 70% orthoclase and 30% plagioclase.

Tiger's eye

quartz replacement of fibrous crocidolite asbestos, streak=yellow brown, chatoyant with asbestos needles, gold yellow, gold brown. A yellow fibrous quartz which includes brilliant scales of colored minerals such as hematite or chromium mica.

Stylolites

Pressure dissolution can take place once a rock is fully cemented to produce irrefular or suture planes.

Quartz Sandstone

which among these rock types would be most porous:

-Conglomerate

-Quartz Sandstone

-Shale

-Greywacke

1 Si atom and 4 oxygen atoms

the basic unit of silicates is composed of how many Si and O atoms?

Trapezohedron

Which of the following refers to the closed crystal form composed of six faces of which the three faces at the top alternate with the three faces at the bottom, the two sets of faces being offset by 60 degrees?

-Cube

-Dipyramid

-Rhombohedron

-Trapezohedron

Tourmaline

Known as Brazilian Emerald?

Serpentine

Known as Verde Antique

Jamesonite

Known as Feather ore

Pyrrhorite

Known as Magnetic pyrite.

Barite

Known as Crested Roses.

Nmineral

In the Becke Line Method, the bright halo of light moves away from the mineral upon increasing the free working distance. This means that:

-Nmineral=Nmedium

-Nmineral>Nmedium

-Nmineral

False

True or False: Unpolarized light vibrates in all directions parallel to a ray path.

Black

How do opaque minerals appear in Plane Polarized Light?

Orthoscopin XPL

The interference color or birefringence is observed in?

Olivine

A mineral was observed to be pleochroic in brown under the microscope. The mineral is possibly:

-Hornblende

-Olivine

-Biotite

-Muscovite

Psephitic

Clayey sedimentary rocks may be described by the following except:

-argillaceous

-lutaceous

-pelitic

-psephitic

Saussurite

A mineral aggregrate which is formed as a hydrothermal and metamorphic alteration product of plagioclase feldspar.

Pyroclastic breccia

rock containing at least 75% blocks and bombs.

Ash tuff

rock dominated by ash; sometimes simply referred to as tuff.

Lapilli tuff

Rock dominated by lapilli.

Tuff breccia

rock containing 25% to 75% blocks and/or bombs.

Monzonite

A plutonic rock with 35-65% K-feldspar, 35-65% plagioclase, and quartz-poor (

deuteric

Type of alteration that occur at relatively very high temperature and pressure.

Allotriomorphic

In describing an igneous rock, this term is used when most in the grains in the rock are anhedral.

Idiomorphic

In describing an igneous rock, having the proper form or shape —used of minerals whose crystalline growth has not been interfered with.

Hypidiomorphic

A texture of igneous rocks in which the greater proportion of the crystallized minerals have subhedral forms.

Porphyritic

describing an igneous rock composed of both large and small crystals.

William Nicol

invented the polarizing microscope in 1828 that permitted study of the behavior of light in crystalline substances.

James Dwight Dana

(1813-1895) A concordist who defended the harmony of science and religion, especially Genesis and Day Age view of origins. Wanted to reconcile science and the Bible. Geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of mountain-building, volcanic activity, and the origin and structure of continents and oceans around the world.

Alfred Wegener

A German scientist who proposed the theroy of continental drift. His hypothesis was controversial and not widely accepted until the 1950s, when numerous discoveries such as palaeomagnetism provided strong support for continental drift, and thereby a substantial basis for today's model of plate tectonics.

Authigenesis

The process by which new minerals form

in a sediment or sedimentary rock during or after deposition.

Diagenesis

chemical, physical, and biological changes that take place after sediments are deposited. A collective term for all the chemical, physical, and biological changes that take place after sediments are deposited and during and after lithification.

True

True or False: 1ce in glacier is a mineral but water is not.

Isometric

For all minerals except those in the _______-system, the velocity of light is different as the light travels along different directions in the crystal.

Tungsten

The chemical with the highest melting point.

Phase diagram

a graph showing the conditions at which a substance exists as a solid, liquid, or vapor.

Max Von Laue

man to first wonder whether or not crystals had a pattern.

Georgius Agricola

German "Father of Mineralogy"; wrote De Re Metallica.