On a white quartzite, (2) In limonite gossan with wulfenite crystalsrosasite. (3) On joint surfaces of metamorphosed dolomitic limestone. Related to paratacamite.
IMA Status:
Approved IMA 2003 (Dana # Added)
Locality:
Mina Los Tres Presidentes, Sierra Gorda, Chile (type locality). Also from (2) the Kali Kafi mine, Anarak, Iran and from (3) the Chah Khouni mine, Anarak, Iran Link to MinDat.org Location Data.
Name Origin:
Named for G.F. Herbert Smith (1872-1953), of the British Museum (Natural History), who discovered paratacamite.
Brittle - Generally displayed by glasses and most non-metallic minerals.
Habit:
Aggregates - Made of numerous individual crystals or clusters.
Habit:
Rhombohedral Crystals - Occurs as well-formed crystals showing rhobohedral crystals.
Hardness:
3-3.5 - Calcite-Copper Penny
Luster:
Vitreous - Adamantine
Streak:
green
Optical Properties of Herbertsmithite
Gladstone-Dale:
CI meas= 0.033 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2184,KPDmeas= 0.2132,KC= 0.2204 Ncalc = 1.83 - 1.87
Optical Data:
Uniaxial (-), e=1.817, w=1.825, bire=0.0080.
Calculated Properties of Herbertsmithite
Electron Density:
Bulk Density (Electron Density)=3.59 gm/cc note: Specific Gravity of Herbertsmithite =3.76 gm/cc.
Fermion Index:
Fermion Index = 0.0060902254 Boson Index = 0.9939097746
Photoelectric:
PEHerbertsmithite = 28.19 barns/electron U=PEHerbertsmithite x rElectron Density= 101.29 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Herbertsmithite is Not Radioactive
Chemical Formula: 