Name/Title
Rutite-QuartzEntry/Object ID
2004.1.79Description
Chemical Composition: TiO2, Titanium Oxide
Crystal System: Tetragonal System
Description: Common Name:Rutite-Quartz
Group Name: Oxides-Silicates
Chemistry: TiO2, Titanium Oxide
Location: Minas, Brazil
Description: Clear and white crystals on flat base.
PHYSICAL CHARACTERISTICS:
Color is black or reddish brown in large thick crystals or golden yellow or rusty yellow as inclusions or in thin crystals.
Luster is adamantine to submetallic.
Transparency: Crystals are transparent in rather thin crystals otherwise opaque.
Crystal System is tetragonal; 4/m 2/m 2/m
Crystal Habits include eight sided prisms and blocky crystals terminated by a blunt four sided or complex pyramid. The prisms are composed of two four sided prisms with one of the prisms being dominant. Crystals with some twins forming hexagonal or octahedral circles. A very common habit is thin acicular needles (especially as inclusions in other minerals) or as blades.
Cleavage is good in two directions forming prisms, poor in a third (basal).
Fracture is conchoidal to uneven.
Hardness is 6 - 6.5
Specific Gravity is 4.2+ (slightly heavy)
Streak is brown
Other Characteristics: Striations lengthwise on crystals, high refractive index (2.63) gives it a sparkle greater than diamond (2.42).
Associated Minerals are quartz, tourmaline, barite, hematite and other oxides and silicates.
Best Field Indicators are crystal habit, streak, hardness, color and high index of refraction (luster).
Fracture: conchoidal
Hardness: 6 Orthoclase
Luster: Metallic
Occurrence: Rutile is a common accessory mineral in high-temperature and high-pressure metamorphic rocks and in igneous rocks.
Rutile is the preferred polymorph of TiO2 in such environments because it has the lowest molecular volume of the three polymorphs; it is thus the primary titanium bearing phase in most high pressure metamorphic rocks, chiefly eclogites. Brookite and anatase are typical polymorphs of rutile formed by retrogression of metamorphic rutile.
Within the igneous environment, rutile is a common accessory mineral in plutonic igneous rocks, although it is also found occasionally in extrusive igneous rocks, particularly those which have deep mantle sources such as kimberlites and lamproites. Anatase and brookite are found in the igneous environment particularly as products of autogenic alteration during the cooling of plutonic rocks; anatase is also found formed within placer deposits sourced from primary rutile.
Notable Occurrences include Minas Gerias, Brazil; Swiss Alps; Arkansas, USA and some African locallities.
Rock Type: Sedimentary
Specific Gravity: 4.2
Streak: brown
Variety: Rutile is an interesting, varied and important mineral. Rutile is a major ore of titanium, a metal used for high tech alloys because of its light weight, high strength and resistance to corrosion. Rutile is also unwittingly of major importance to the gemstone markets. It also forms its own interesting and beautiful mineral specimens.
Microscopic inclusions of rutile in quartz, tourmaline, ruby, sapphire and other gemstones, produces light effects such as cat's eye and asterisms (stars). A beautiful stone produced by large inclusions of golden rutile needles in clear quartz is called rutilated quartz. Rutilated quartz is sometimes used as a semi-precious stone and/or for carvings. This stone is produced because at high temperatures and pressure, n(SiO2)-n(TiO2) is in a stable state but as temperatures cool and pressure eases the two separate with rutile crystals trapped inside the quartz crystals.Collection
Suomynona Mineral CollectionAcquisition
Accession
2004.1Source or Donor
Suomynona Mineral CollectionAcquisition Method
DonationDimensions
Width
4-1/2 inDepth
10-3/4 inLength
12-1/2 inWeight
13.42 ozDimension Notes
Dimension taken at widest pointsLocation
Category
PermanentMoved By
Curtis GardnerDate
May 24, 2023Notes
Added current locationLocation
Drawer
North endShelf
top center, top centerWall
South CenterHallway
Discovery HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Scott LonganDate
August 26, 2009
