General Howlite Information Chemical Formula: |
Ca2B5SiO9(OH)5 |
Composition: |
Molecular Weight = 391.32 gm |
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Calcium 20.48 % Ca 28.66 % CaO |
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Silicon 7.18 % Si 15.35 % SiO2 |
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Boron 13.81 % B 44.48 % B2O3 |
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Hydrogen 1.29 % H 11.51 % H2O |
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Oxygen 57.24 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
Ca2B5SiO9(OH)5 |
Environment: |
Secondary mineral in arid environments. |
IMA Status: |
Valid Species (Pre-IMA) 1868 |
Locality: |
Tick Canyon, Los Angeles Co., California. Link to MinDat.org Location Data. |
Name Origin: |
Named after Henry How of Nova Scotia when he first described it in 1868. |
Name Pronunciation: |
Howlite |
Synonym: |
ICSD 15178 |
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PDF 26-1404 |
| | Howlite Image
Images:
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Howlite Crystallography Axial Ratios: |
a:b:c =1.3697:1:0.9217 |
Cell Dimensions: |
a = 12.78, b = 9.33, c = 8.6, Z = 4; beta = 104.83° V = 991.28 Den(Calc)= 2.62 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 21/c |
X Ray Diffraction: |
By Intensity(I/Io): 6.207(1), 3.894(0.95), 3.094(0.65), |
Crystal Structure:
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Mouse
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| Physical Properties of Howlite Cleavage: |
None |
Color: |
Colorless, White. |
Density: |
2.58 |
Diaphaneity: |
Translucent |
Fracture: |
Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments. |
Habit: |
Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite). |
Habit: |
Massive - Uniformly indistinguishable crystals forming large masses. |
Habit: |
Nodular - Tuberose forms having irregular protuberances over the surface. |
Hardness: |
2.5-3.5 - Finger Nail-Copper Penny |
Luminescence: |
Fluorescent, Long UV=bright sky blue. |
Luster: |
Earthy (Dull) |
Magnetism: |
Nonmagnetic |
Streak: |
white |
| Optical Properties of Howlite 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 Optical Data: |
Biaxial (-), a=1.58, b=1.59, g=1.6, bire=0.0200, 2V(Calc)=88, 2V(Meas)=60-90. Dispersion none. |
Pleochroism (x): |
none. |
Pleochroism (y): |
none. |
Pleochroism (z): |
none. |
| Calculated Properties of Howlite Electron Density: |
Bulk Density (Electron Density)=2.62 gm/cc |
note: Specific Gravity of Howlite =2.62 gm/cc. Fermion Index: |
Fermion Index = 0.03 |
Boson Index = 0.97 Photoelectric: |
PEHowlite = 2.97 barns/electron |
U=PEHowlite x rElectron Density= 7.79 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Howlite is Not Radioactive | Howlite Classification Dana Class: |
25.03.05.01 (25)Anhydrous Borates Containing Hydroxyl or Halogen |
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(25.03)Dana Type |
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(25.03.05)Dana Group |
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Strunz Class: |
06.CB.20 06 - BORATES |
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06.C - Triborates |
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06.CB -Ino-triborates |
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| Other Howlite Information References: |
NAME( MinRec) PHYS. PROP.(Collectors Book of Fluorescent Minerals) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990) |
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 18 - WWW-MINCRYST Search for Howlite using: Visit our Advertisers for Howlite : A Bijoux Google Search for HowliteAdam's Minerals Google Search for Howlite Cape Minerals Google Search for Howlite Dakota Matrix Minerals Google Search for Howlite Excalibur Mineral Corp. Google Search for Howlite Exceptional Minerals Google Search for Howlite John Betts Fine Minerals Search for Howlite McDougall Minerals Google Search for Howlite Mineral News Website Link Rock and Mineral Shows Google Search for Howlite Weinrich Minerals, Inc. Google Search for Howlite Ask about Howlite here : Print or Cut-and-Paste your Howlite Specimen Label here :
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