K-Feldspar and Plagioclase Feldspar

Feldspars have two cleavage planes that intersect at 90°. Fragments of pure feldspar crystals thus tend to form rectangular blocks with irregular ends. Feldspars have vitreous lusters and occur in opaque shades of white to gray to pink to very dark gray.


LAB TEST #1- MINERALS Flashcards | Quizlet

a POTASSIUM feldspar-- KAlSi3O8 -- light glassy lust, reddish pinkish tan colors, hardness of 6.0, 2 PLANES OF CLEAVAGE AT 90 DEGREES, leaves no streak, specific gravity of 2.65, feathery planes on the ends (rough), otherwise just known as orthoclase


Quartz - University of Pittsburgh

A large broken quartz crystal has irregular fractures but no fractures. Quartz is a harder mineral than feldspar (H = 7) and in igneous and metamorphic rocks is normally translucent and dark to light gray in color (it depends in part on how dark or light the surrounding minerals are).


Mineral Lab | Minerals | Quartz

B. surfaces that are not obvious.10 Cross sections of mineral samples to illustrate degrees of development of cleavage—the tendency for a mineral to break along one or more sets of parallel planar surfaces called cleavage planes. parallel surfaces.2).


Mineral Identification Key - Table IID-1

The Mineral Identification Key Table IID-1: Nonmetallic Luster, Hardness Greater Than 3 but Less Than 5½, and Prominent Cleavage: (Can not be scratched by a copper penny, can be scratched by a knife, streak white or none.)


Mineral Identification Key - Central Bucks School District

Fracture Cleavage Cleavage Fracture Mineral Identification Key Directions: Observe and test each of your mineral samples and use their properties to narrow down your choices. Read the key from left to right in order to correctly identify the mineral name.


Mineral ID Charts - Napa Valley College

Mineral H SG Streak Color and/or Luster Form Cleavage/Fracture Diagnostic properties Calcite CaCO 3 3 2.7 White Usually colorless, white, or yellow, can be green, brown, or pink.


Mineral Identification Guide - Mining Matters

Cleavage: good - observe mica's cleavage by holding the mineral up to the light and turning it slowly to see the slick, flashy surface. Crushing a tiny bit in your hand will leave little sparkles where light reflects off the crushed sample.


What is a Cleavage Plane? - Definition from Corrosionpedia

A cleavage plane is the fracture of a crystal or metal by crack propagation across a crystallographic plane or cleavage plane, or the tendency to cleave or split along definite crystallographic planes.


Minerals - Cleavage and Fracture

Cleavage is the tendency of a mineral to break along smooth planes parallel to zones of weak bonding. Fracture is the tendency of a mineral to break along curved surfaces without a definite shape.


Mineral Properties - University of Wisconsin–Oshkosh

Generally clear to white; One perfect cleavage, may show up to 3 cleavages; Easily scratched with a fingernail. Back to Environmental Lab Schedule Back to Environmental Lab Page


Mineral Identification Key Cleavage

Cleavage refers to the way some minerals break along certain lines of weakness in their structure. Mica is a good example – breaking along very closely spaced flat planes that yield thin "sheets." Mica is a good example – breaking along very closely spaced flat planes that yield thin "sheets."


From Matter to Minerals - Columbia University

A mineral is a naturally occurring, inorganic, homogeneous solid with a definite (though variable) chemical composition and an ordered atomic arrangement.. A crystal is a regular geometric solid bounded by smooth plane surfaces (maybe a mineral crystal but there are also organic crystalline materials). The regular geometry is due to the ordered atomic arrangement.


Minerals - Geology (U.S. National Park Service)

Cleavage: The tendency of a mineral to break (cleave) along weak planes. Color: Most minerals have a distinct color while others are variable in color. Hardness: A measure of a mineral's …


Rock and Mineral identification Flashcards | Quizlet

directions that a rock or mineral can be easily split. It is a tendency to split along a definite plane yielding a flat surface. Rocks or minerals perfect cleavage may …


Mineral - Wikipedia

When a mineral is broken in a direction that does not correspond to a plane of cleavage, it is termed to have been fractured. There are several types of uneven fracture. The classic example is conchoidal fracture, like that of quartz; rounded surfaces are created, which are marked by smooth curved lines.


GeoMan's Mineral Identification: Non-metallic, H.<2.5

A common alteration mineral found in mafic igneous rocks (alteration of the ferromagnesian minerals to chlorite results in the greenish tint common to altered basalt, …


University of Minnesota's Mineral Pages: Plagioclase Feldspar

Plagioclase minerals are typically white or gray, hard blocky crystal masses that exhibit cleavage in two directions that are nearly at right angles. They are particularly common in igneous and metamorphic rocks, where they often form the bulk of the rock's volume.


USGS Geology and Geophysics

Micas are another group of silicate minerals composed of varying amounts of potassium, magnesium, iron as well as aluminum, silicon and water. Biotite All micas form flat, book-like crystals that peal apart into individual sheets on cleavage planes.


University of Minnesota's Mineral Pages: Potassium Feldspar

A combination of hardness, non-metallic luster and two good cleavage directions at right angles to one another serves to distinguish the feldspar minerals from most of the common rock-forming minerals.


Physical Properties of Minerals - Tulane University

Cleavage is usually induced in the mineral when it is extracted from the rock when it is found, and can usually be seen as planes running through the mineral. Therefore, you do not have to break the mineral in order to see its cleavage.


Mineral Identification Table - Stephen J. Reynolds

Mineral Identification Table Minerals for This Lab and Some Physical Properties They Possess. ... Cleavage 2 planes at close to right angles, twinning striations. Streak white. ... (K,Al Silicate) Luster nonmetallic. Color varies white, cream, or pink. Hardness 6. Two directions of cleavage at right angles. Streak white. Has glossy appearance ...


Cleavage planes of different minerals including quartz ...

Cleavage of minerals Geology IN IN: Cleavage of minerals A cleavage plane is a plane of structural weakness along which a mineral is likely to split smoothly. Cleavage thus refers to the splitting of a crystal between two parallel atomic pla


Chapter 2 Lab - Jan Rasmussen.com

Mineral Descriptions Chapter 2 Lab. 2 ... cleavage planes, but they are crystal faces. The hardness of hematite is ... has a slightly pinkish or flesh colored tinge to it. It can also be clear or blue or yellow or almost any other color, but it does have a white streak. The most