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Calaveras River Canyon, Valley Springs area, Calaveras Co., California, USAi
Regional Level Types
Calaveras River CanyonCanyon
Valley Springs areaArea
Calaveras Co.County
CaliforniaState
USACountry

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Location is approximate, estimate based on other nearby localities.
 
Latitude & Longitude (WGS84): 38° North , 120° West (est.)
Margin of Error:~43km
Locality type:Canyon
Köppen climate type:Csa : Hot-summer Mediterranean climate


Calaveras County Quartz with Epidote inclusions

QUARTZ
Short to long prismatic crystals common. Luster ranges from dull to glassy. Doubly terminated crystals, Tabular crystals and parallel growth aggregates occur frequently. Equant, pseudocubic crystals as well as choice fadens, both with Chlorite inclusions have been found, but these crystals are quite rare and highly prized.


Comments: Quartz crystals from the Valley Springs area are most sought after for their beautiful landscape-like inclusions of Epidote, Chlorite and altered matrixes in various combinations. Pockets are located in Lateritic soils derived from the decomposition of greenstones and are almost always completely collapsed - their contents sometimes scattered for several feet. It is unfortunate that this unique locality is closed to collecting due to large sub-divisions devouring the productive areas.

EPIDOTE
Primatic crystals from 2mm to 15mm with vertical striations and typical wedge terminations. Single crystals are found loose in pocket clay and as inclusions within Quartz crystals. Crystals are a deep olive green to light green in color. Also massive and massive crystalline. Less commonly found in pockets are unusual, dense groupings of unterminated crystals associated with Quartz. The terminations of these groups being found loose in the pocket clays and included within Quartz crystals. Epidote crystals from the Valley Springs area can be quite similar in habit to those from the New Melones Reservoir to the south.

CHLORITE
Deep green to unusual light olive green micro vermiform masses.
Found as inclusions within Quartz crystals and coatings on them. Commonly as multiple stage "phantoms". On rare occasions, Chlorite can also be observed coating the "threads" of faden Quartz crystals - thus making for very attractive and unusual rarities. Exposed chlorite on the surface of quartz crystals is often oxidized to an earthy brown.

ALBITE
Uncommonly found in pockets are small 2 - 6 mm opaque tabular, untwinned crystals of albite in groupings on matrix normally stained orange by iron oxide coatings.

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List


3 valid minerals.

Detailed Mineral List:

Albite
Formula: Na(AlSi3O8)
Reference: Harper, Jake (1990-2110), Field work.
'Chlorite Group'
Habit: Deep green to unusual light olive green micro vermiform masses.
Colour: green
Description: Found as Deep green to unusual light olive green inclusions within Quartz crystals - commonly as multiple stage "phantoms". On rare occasions, Chlorite can also be observed coating the "threads" of Faden Quartz crystals - thus making for very attractive and unusual rarities.
Reference: Jake Harper: Field work, 1990 - 2110.
Epidote
Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Habit: Primatic crystals from 2mm to 15mm with vertical striations and typical wedge terminations. Crystals are a deep olive green to light green in color. Also massive and massive crystalline.
Colour: green
Description: Single crystals are found loose in pocket clay and as inclusions within Quartz crystals. Epidote crystals from the Valley Springs area can be quite similar in habit to those from the New Melones Reservoir to the south. Less commonly found in pockets are unusual, dense clusters of unterminated crystals associated with Quartz. The terminations of these groups being found loose in the pocket clays.
Reference: Jake Harper: Field work, 1990 - 2110.
Quartz
Formula: SiO2
Habit: Short to long prismatic crystals common. Luster ranges from dull to glassy. Doubly terminated crystals, Tabular crystals and parallel growth aggregates occur frequently.
Colour: colorless
Description: Quartz crystals from the Valley Springs area are most sought after for their beautiful lanscape-like inclusions of Epidote, Chlorite and altered matrixes in various combinations. Pockets are located in Lateritic soils derived from the decomposition of greenstones and are almost always completely collapsed - their contents sometimes scattered for several feet. It is unfortunate that this unique locality is closed to collecting due to large sub-divisions devouring productive areas.
Reference: Jake Harper: Field work, 1990 - 2110.

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
'Quartz'4.DA.05SiO2
Group 9 - Silicates
'Albite'9.FA.35Na(AlSi3O8)
'Epidote'9.BG.05a{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Unclassified Minerals, Rocks, etc.
'Chlorite Group'-

List of minerals arranged by Dana 8th Edition classification

Group 58 - SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
Epidote58.2.1a.7{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Group 76 - TECTOSILICATES Al-Si Framework
Al-Si Framework with Al-Si frameworks
Albite76.1.3.1Na(AlSi3O8)
Unclassified Minerals, Rocks, etc.
'Chlorite Group'-

List of minerals for each chemical element

HHydrogen
H Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
OOxygen
O AlbiteNa(AlSi3O8)
O Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
O QuartzSiO2
NaSodium
Na AlbiteNa(AlSi3O8)
AlAluminium
Al AlbiteNa(AlSi3O8)
Al Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
SiSilicon
Si AlbiteNa(AlSi3O8)
Si Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Si QuartzSiO2
CaCalcium
Ca Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
FeIron
Fe Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Harper, Jake (1990-2110), Field work.
Jackson, Bob (1994), Personal communication.


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