Lopezite Mineral Data

Lopezite Mineral Data
Search Webmineral :
   
Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images       News Help About



[Newest Minerals] [Equipment] [Analytical Services] [About Us] [Mineral Gallery] [eBay Store]
See Also: [Diamond Crystals] [Mineral News] [Hudson Institute] [Minerals on CDROM]
Rare Minerals, Meteorites, Equipment and Analytical Services
Excalibur Mineral Company, World leaders in the supply of rare species
Serving the scientific and collector communities since 1974


General Lopezite Information

Help on Chemical Formula: Chemical Formula: K2Cr2O7
Help on Composition: Composition: Molecular Weight = 294.18 gm
   Potassium  26.58 %  K    32.02 % K2O
   Chromium   35.35 %  Cr   67.98 % CrO3
   Oxygen     38.07 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K2Cr2O7
Help on Environment: Environment: Rare secondary mineral in vugs in massive nitrate rock.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1937
Help on Locality: Locality: In Chile, in Tarapaca, from Oficina Rosario, Huara, Pampa del Iquique; Oficina Maria Elena, near Tocopilla, Pampa del Tocopilla; and at Zapiga. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Emiliano Lopez Saa (1871-1959), Iquique, Chile, Chilean mining engineer and mineral collector long associated with the Chilean nitrate industry.
Help on Name Pronunciation: Name Pronunciation: Lopezite Say LOPEZITE
Help on Synonym: Synonym: ICSD 10371
  PDF 27-380
 

Lopezite Image

Click Here for Larger Lopezite Image in a New Browser Window Images:
Click Here for Larger Lopezite Image

Lopezite

Comments: yellowish granular lopezite.
Location: Tarapaca, Chile. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Lopezite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =0.5597:1:0.5507
Help on Cell Dimensions: Cell Dimensions: a = 7.5, b = 13.4, c = 7.38, Z = 4; alpha = 98°, beta = 90.85°, gamma = 96.217° V = 730.07 Den(Calc)= 2.68
Help on Crystal System: Crystal System: Triclinic - PinacoidalH-M Symbol ( 1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.32(1), 3.49(0.3), 3.68(0.2),
Click Here for Large Lopezite Structure Window Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
 Help on Above


Weakley T J R , Ylvisaker E R , Yager R J , Stephens J E , Wiegel R D , Mengis M , Wu P , Photinos P , Abrahams S C , Acta Crystallographica, Section B , 60 (2004) p.705-715, Phase transitions in K2Cr3O7 and structural redetermination of phase II, Locality: synthetic, Sample: Crystal 2

 

Physical Properties of Lopezite

Help on Cleavage: Cleavage: {010} Perfect, {100} Distinct, {001} Distinct
Help on Color: Color: Orange red, Red.
Help on Density: Density: 2.69
Help on Diaphaneity: Diaphaneity: Transparent
Help on Hardness: Hardness: 2.5 - Finger Nail
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: light yellow
 

Optical Properties of Lopezite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.04 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.036 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.28,KPDmeas= 0.2789,KC= 0.2905
Ncalc = 1.78
Help on Optical Data: Optical Data: Biaxial (+), a=1.714, b=1.732, g=1.805, bire=0.0910, 2V(Calc)=56, 2V(Meas)=50.
 

Calculated Properties of Lopezite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.59 gm/cc
note: Specific Gravity of Lopezite =2.68 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PELopezite = 10.72 barns/electron
U=PELopezite x relectron= 27.75 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 370.25 (Gamma Ray American Petroleum Institute Units)
Concentration of Lopezite per GRapi unit = 0.27 (%)

Estimated Radioactivity from Lopezite - barely detectable

 

Lopezite Classification
Help on Dana Class: Dana Class: 35.02.01.01 (35)Anhydrous Chromates
  (35.02)where (A+)2 X2O7
  (35.02.01)Dana Group
 
35.02.01.01 Lopezite K2Cr2O7 P1 1
Help on Strunz Class: Strunz Class: 07.FD.05 07 - SULFATES (SELENATES, TELLURATES)
  07.F - Chromates
  07.FD -Dichromates
 
07.FD.05 Lopezite K2Cr2O7 P1 1
 

Other Lopezite Information
Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Lopezite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

Search for Lopezite using:

Google
 
Web webmineral.com
[ALTAVISTA] [AOL] [bing] [GeoScienceWorld] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Lopezite :

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Excalibur Minerals

Exceptional Minerals

Fabre Minerals

John Betts Fine Minerals

Lapis Mineral Journal

Mineral News

UV Tools

Wrights Rock Shop

Translate Lopezite Mineral Data :

Ask about Lopezite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Espaņol

Print or Cut-and-Paste your Lopezite Specimen Label here :

Lopezite

K2Cr2O7
Dana No: 35.02.01.01 Strunz No: 07.FD.05
Locality:

 

Notes: