Mineralogy Database

Howlite Mineral Data

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General Howlite Information

Help on Chemical  Formula: Chemical Formula: Ca2B5SiO9(OH)5
Help on Composition: Composition: Molecular Weight = 391.32 gm
   Calcium   20.48 %  Ca   28.66 % CaO
   Silicon    7.18 %  Si   15.35 % SiO2
   Boron     13.81 %  B    44.48 % B2O3
   Hydrogen   1.29 %  H    11.51 % H2O
   Oxygen    57.24 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca2B5SiO9(OH)5
Help on Environment: Environment: Secondary mineral in arid environments.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1868
Help on Locality: Locality: Tick Canyon, Los Angeles Co., California. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after Henry How of Nova Scotia when he first described it in 1868.
Help on Name Pronunciation: Name Pronunciation: Howlite Say HOWLITE
Help on Synonym: Synonym: ICSD 15178
  PDF 26-1404

Howlite Image

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Comments: Silky nodule of howlite.
Location: Windsor, Nova Scotia, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Howlite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.3697:1:0.9217
Help on Cell Dimensions: Cell Dimensions: a = 12.78, b = 9.33, c = 8.6, Z = 4; beta = 104.83° V = 991.28 Den(Calc)= 2.62
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 6.207(1), 3.894(0.95), 3.094(0.65),

Physical Properties of Howlite

Help on Cleavage: Cleavage: None
Help on Color: Color: Colorless, White.
Help on Density: Density: 2.58
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses.
Help on Habit: Habit: Nodular - Tuberose forms having irregular protuberances over the surface.
Help on Hardness: Hardness: 2.5-3.5 - Finger Nail-Copper Penny
Help on Luminescence: Luminescence: Fluorescent, Long UV=bright sky blue.
Help on Luster: Luster: Earthy (Dull)
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: white

Optical Properties of Howlite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.007 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2252,KPDmeas= 0.2287,KC= 0.2269
Ncalc = 1.59
Help on Optical Data: Optical Data: Biaxial (-), a=1.58, b=1.59, g=1.6, bire=0.0200, 2V(Calc)=88, 2V(Meas)=60-90. Dispersion none.
Help on Pleochroism (x): Pleochroism (x): none.
Help on Pleochroism (y): Pleochroism (y): none.
Help on Pleochroism (z): Pleochroism (z): none.

Calculated Properties of Howlite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.62 gm/cc
note: Specific Gravity of Howlite =2.62 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PEHowlite = 2.97 barns/electron
U=PEHowlite x rElectron Density= 7.79 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Howlite is Not Radioactive

Howlite Classification

Help on  Dana Class: Dana Class: (25)Anhydrous Borates Containing Hydroxyl or Halogen
  (25.03)Dana Type
  (25.03.05)Dana Group Howlite Ca2B5SiO9(OH)5 P 21/c 2/m
Help on  Strunz Class: Strunz Class: 06.CB.20 06 - BORATES
  06.C - Triborates
  06.CB -Ino-triborates
06.CB.20 Howlite Ca2B5SiO9(OH)5 P 21/c 2/m

Other Howlite Information

Help on References: References: NAME( MinRec) PHYS. PROP.(Collectors Book of Fluorescent Minerals) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Howlite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineral and Gemstone Kingdom
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - Tradeshop.com - The Rainbow of Gems

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Dana No: Strunz No: 06.CB.20





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