Name/Title
Quartz on HematiteEntry/Object ID
2004.1.19Description
Assemblage Zone: pegmatite dikes
Chemical Composition: SiO2
Crystal System: Triclinic System
Description: Common Name: Quartz on Hematite
Chemistry: SiO2 , Silicon dioxide
Class: Silicates
Subclass: Tectosilicates
Group: Quartz
Uses: silica for glass, electrical components, optical lenses, abrasives, gemstones, ornamental stone, building stone, etc.
"HEMATITE"
Chemical Formula: Fe2O3, Iron Oxide
Class: Oxides and Hydroxides
Group: Hematite
Uses: Very important ore of iron, as a pigment and as mineral specimens."
Location: Jinlong Iron Mine, Quandong Province, China
Description: Clear quartz crystals and bladed hemattie crystals.
PHYSICAL CHARACTERISTICS QUARTZ:
Color is as variable as the spectrum, but clear quartz is by far the most common color followed by white or cloudy (milky quartz). Purple (Amethyst), pink (Rose Quartz), gray or brown to black (Smoky Quartz) are also common. Cryptocrystalline varieties can be multicolored.
Luster is glassy to vitreous as crystals, while cryptocrystalline forms are usually waxy to dull but can be vitreous.
Transparency: Crystals are transparent to translucent, cryptocrystalline forms can be translucent or opaque.
Crystal System is trigonal; 3 2.
Crystal Habits are again widely variable but the most common habit is hexagonal prisms terminated with a six sided pyramid (actually two rhombohedrons). Three of the six sides of the pyramid may dominate causing the pyramid to be or look three sided. Left and right handed crystals are possible and identifiable only if minor trigonal pyramidal faces are present. Druse forms (crystal lined rock with just the pyramids showing) are also common. Massive forms can be just about any type but common forms include botryoidal, globular, stalactitic, crusts of agate such as lining the interior of a geode and many many more.
Cleavage is very weak in three directions (rhombohedral).
Fracture is conchoidal.
Hardness is 7, less in cryptocrystalline forms.
Specific Gravity is 2.65 or less if cryptocrystalline. (average)
Streak is white.
Other Characteristics: Striations on prism faces run perpendicular to C axis, piezoelectric (see tourmaline) and index of refraction is 1.55.
Associated Minerals are numerous and varied but here are some of the more classic associations of quartz (although any list of associated minerals of quartz is only a partial list): amazonite a variety of microcline, tourmalines especially elbaite, wolframite, pyrite, rutile, zeolites, fluorite, calcite, gold, muscovite, topaz, beryl, hematite and spodumene.
Best Field Indicators are first the fact that it is very common (always assume transparent clear crystals may be quartz), crystal habit, hardness, striations, good conchoidal fracture and lack of good cleavage.
PHYSICAL CHARACTERISTICS HEMATITE:
Color is steel or silver gray to black in some forms and red to brown in earthy forms. Sometimes tarnished with iridescent colors when in a hydrated form (called Turgite).
Luster is metallic or dull in earthy and oolitic forms.
Transparency: Crystals are opaque.
Crystal System is trigonal; bar 3 2/m
Crystal Habits include tabular crystals of varying thickness sometimes twinned, micaceous (specular), botryoidal and massive. also earthy or oolitic.
Cleavage is absent. However, there is a parting on two planes.
Fracture is uneven.
Hardness is 5 - 6
Specific Gravity is 5.3 (slightly above average for metallic minerals)
Streak is blood red to brownish red for earthy forms.
Associated Minerals include jasper (a variety of quartz) in banded iron formations (BIF or Tiger Iron), dipyramidal quartz, rutile, and pyrite among others.
Best Field Indicators are crystal habit, streak and hardness
Fracture: Conchoidal
Hardness: 7 Quartz
Luster: Waxy
Occurrence: Quartz occurs in hydrothermal veins as gangue along with ore minerals. Large crystals of quartz are found in pegmatites.
The mineral can precipitate out of water and collect in layers at the bottom of a lake, spring, or other standing water. Hematite can also occur without water, however, usually as the result of volcanic activity.
Rock Type: Igneous
Specific Gravity: 2.65
Streak: Whie
Texture: Crystalline
Variety: Quartz is the most common mineral on the face of the Earth. It is found in nearly every geological environment and is at least a component of almost every rock type. It frequently is the primary mineral, >98%. It is also the most varied in terms of varieties, colors and forms. This variety comes about because of the abundance and widespread distribution of quartz..
Hematite has several varieties, each with their own unique names. Hematite Rose is a circular arrangment of bladed crystals giving the appearance of the flower of a rose. Tiger Iron is a sedimentary deposit of approximately 2.2 billion years old that consists of alternating layers of silver gray hematite and red jasper, chert or even tiger eye quartz.. Kidney Ore is the massive botryoidal form and gives the appearance of lumpy kidney-like masses. Oolitic Hematite is a sedimentary formation that has a reddish brown color and an earthy luster and is composed of small rounded grains. Specularite is a micaceous or flaky stone that is sparkling silver gray and sometimes used as an ornamental stone.Collection
Suomynona Mineral CollectionAcquisition
Accession
2004.1Source or Donor
Suomynona Mineral CollectionAcquisition Method
DonationDimensions
Width
9 inDepth
5-1/2 inLength
12 inDimension Notes
Dimension taken at widest pointsLocation
Location
Shelf
Right, RightRoom
Mentzer HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Rawley WyattDate
March 6, 2015Location
Wall
NorthBuilding
Storage (old gift shop upstairs)Category
PermanentMoved By
Rawley WyattDate
May 20, 2014Location
Container
rightDrawer
top tierShelf
south side, south sideWall
centerHallway
Discovery HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Wendy MondryDate
August 25, 2009Location
Shelf
BottomCabinet
Case # 7Room
Mentzer HallBuilding
Crater Rock MuseumCategory
Permanent
