Thorogummite	IMA-GP
Uranium (trace) Thorium	51.5.2.5 (Dana Classification Number)
(Images)	8/A.09-50 (Strunz ID)

Property	Data	Remarks
Named for:	Its Thorium content and gum-like consistancy
Alternate     Name(s):	alpha-Hyblite beta-Hyblite Chlorothorite Hyblite Hydrothorite Hydroxyl-thorite Mackintoshite Maitlandite Nicolayite Pilbarite (a mixture of Kasolite and Thorogummite)	These minor varients of Thorogummite were once considered to be seperate minerals
Mineral Class:	Silicates   Nesosilicates with [SiO4]-4 groups, cations of octahedral and cubic orientation [8+6]     Zircon - Thorogummite series
Chemical     Formula:	(Th, U)2(SiO4)(2 - X)(OH)4X Thorogummite has varying amounts of SiO4 tetrahedrons that are replaced by four hydroxides. This can be represented with several different formulas. The formula that is used here: (Th, U)2(SiO4)(2 - X)(OH)4X The X represents the conversion of one silicate tetrahedron with a negative four charge (-4) to four hydroxides with a negative one charge (-1) each. So that if half the silicate tetrahedrons are replaced by the four hydroxides, where X = 1, the formula would look like this: (Th, U)2SiO4(OH)4 Often though thorogummite's formula is written like this: (Th, U)[SiO4, (OH)4] This formula also reflects the substitution of hydroxides for silicate tetrahedrons.
Chemical     Formula:	Th(SiO4)1-x(OH)4x	Thorium Hydroxy Silicate
Chemical     Composition:	Hydrogen: (H) 0.13% Oxygen: (O) 19.89% Silicon: (Si) 7.86% Thorium: (Th) 72.13%	by weight
Molecular     Weight:	321.72	daltons (amu)
Specific     Radioactivity:	(All radiation is for a 1 gram, fully aged specimen) Specific Activity Dose Rate Becquerels Curies milliRems/hour microSieverts/hour 3.2312 × 1004 8.73 × 10-07 0.42 42.45 Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
Crystalography:	System: Tetragonal- Ditetragonal Dipyramidal Axial Ratios: a:c = 1:0.88568 Cell Dimensions: a = 7.068, c = 6.26, Z = 3; V = 312.73 Den(Calc)= 5.12 H-M Symbol: 4/m 2/m 2/m Space Group: I41/amd X Ray Diffraction: By Intensity(I/Io): 3.537(1) 4.695(0.9) 2.653(0.6)
Habit:	Earthy masses Pseudomorphs of thorite, (short prismatic crystals with a square cross-section and simple pyramidal terminations. On-hand specimen observed with some having a slightly octahedral cross-sections)
Cleavage:	Absent
Fracture:	Earthy
Moh's     Hardness:	5 (1 - en mass)
Density:	4.1 - 4.5 (5.4)	grams/cm3
Color:	Pale yellow, Yellowish brown, White, Buff, Brown, Greenish gray, or Black
Streak:	Pale yellow to White
Luster:	Earthy to Vitreous
Diaphaneity:	Opaque
Pleochroism:	None
Ultra Violet     Fluorescence:	Non-fluorescent
Magnetism:	Non-magnetic
Occurance:	Secondary modification of Thorite.
Associated     Minerals:	Aegirine, Albite, 'Allanite', Almandine, Anatase, 'Apatite', Arsenopyrite, Augite, Barite, Beryl, Biotite, Calcite, Cancrinite, Celestine, Chalcopyrite, 'Chlorite Group', Clinochlore, Diopside, Dolomite, Fluorapatite, Fluorite, 'Gadolinite', Galena, Goethite, Graphite, Gypsum, Hematite, 'Hornblende', Ilmenite, Magnetite, Malachite, Marcasite, Microcline, Molybdenite, Monazite, Muscovite, Nepheline, 'Oligoclase', Orthoclase, Pyrite, Pyrochlore, Pyrrhotite, Quartz, Quartz var: Smoky Quartz, Rutile, Siderite, Spessartine, Sphalerite, Talc, Thorite, Titanite, Tremolite, Uraninite, Uranophane, Wulfenite, Xenotime-(Y), Zircon Mineral   -   > 60% of sites Mineral   -   > 40% of sites Mineral   -   > 20% of sites Minerals   -   Uranium & Thorium mineral links	These are minerals known to be found with Thorogummite
Locations:	Somewhat rare Thorogummite Locations The type locale is now inundated by Buchanan artifical Lake, along the Colorado River, Texas, U.S.A.
Notes:	Strongly radioactive a- and b-particles, g-rays. Always metamict. A product of the alteration of thorite, (Th, U)SiO4

Thorogummite Images

Specimen
(001a)	(001b)	(001c)	(001d)
(001e)	(001f)	(001g)	(001h)
(001i)	(001j)	(001k)	(001l)
(001m)	(001n)	(001o)	(001p)
(001q)	(001r)	(001s)
Fort Dauphin (Tôlanaro) area, Toliara (Tuléar) Province, Madagascar
Specimen Notes Host Matrix - The matrix that the Thorogummite occurs in is primarily Calcite and Quartz. There appears to be very few, if any, vugs in the rock. The Thorogummite appears to have grown cuncurrently with the host rock. Crystals - There are no true crystals of Thorogummite visable anywhere on the specimen. The Thorogummite occurs as either massive deposits or crystal pseudomorphs after Thorite, which is to be expected as it is a thorite chemically combined with water, and not simply hydrated. The massive deposits occur in two forms: sub-opague light 'apricot' yellow ; or crystaline, translucent to sub-transparent light to dark 'apricot' yellow (bottom center of image 001b and image 001e). The lighter colored crystaline massive forms often appear to be cloudy, as in image 001h. The two forms may occur intermixed together, as seen in image 001m. The crystal pseudomorphs after Thorite are in the prismatic form of Thorite. These pseudomorphs can be seen in images 001a and 001f, and 001n thru 001s. They are somewhat erroded and rounded, with the pointed tips all definitely rounded. The lateral edges of the crystal body appear to be truncated in addition to being rounded, as can be seen in images 001o, 001p and 001s. It is possible that this is due to the erosion of the thorogummite during its formation. Diaphaneity - The Thorogummite varies from transparent to translucent, as seen in image (001j). The pseudomorph crystals are mostly translucent, with a few areas opaque, seen in image (001o). Luster - Luster varies from vitreous, image (001j), to sub-vitreous, image (001p). The more transparent Thorogummite is also the more vitreous. The opaque Thorogummite is earthy in luster.     -       -