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Skookumchuck Dam, Bucoda, Thurston County, Washington, USAi
Regional Level Types
Skookumchuck DamDam
BucodaVillage
Thurston CountyCounty
WashingtonState
USACountry

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PhotosMapsSearch
03242930017272038941733.jpg
Boulders after the blast on the north side of the valley in 1969

Skookumchuck Dam, Bucoda, Thurston County, Washington, USA
05798820017272038952132.jpg
The spillway on the south side of the valley in 1970

Skookumchuck Dam, Bucoda, Thurston County, Washington, USA
03242930017272038941733.jpg
Boulders after the blast on the north side of the valley in 1969

Skookumchuck Dam, Bucoda, Thurston County, Washington, USA
05798820017272038952132.jpg
The spillway on the south side of the valley in 1970

Skookumchuck Dam, Bucoda, Thurston County, Washington, USA
02490500017272039017777.jpg
Boulders after the blast on the north side of the valley in 1969

Skookumchuck Dam, Bucoda, Thurston County, Washington, USA
Latitude & Longitude (WGS84):
46° 47' 4'' North , 122° 43' 5'' West
Latitude & Longitude (decimal):
Type:
Nearest Settlements:
PlacePopulationDistance
Bucoda566 (2017)11.6km
Rainier1,985 (2017)11.7km
Tenino1,749 (2017)13.0km
Yelm8,434 (2017)19.5km
Centralia16,753 (2017)19.5km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Washington Agate and Mineral SocietyOlympia, Washington31km
Mindat Locality ID:
15519
Long-form identifier:
mindat:1:2:15519:0
GUID (UUID V4):
0


Zeolites were found in Eocene olivine basalt flows during construction of the Skookumchuck Dam (1969-1971) near Tenino and Bucoda, Thurston County, Washington. Pockets of exceptionally large mesolite crystals were found early in the construction during blasting rock on the north side of the valley. Excellent specimens of stilbite were found later on the south side of the valley during construction of the spillway. Cavities in the basalt reached 1 meter in diameter but most were smaller. Cavities 2 to 6 cm in diameter were lined with pink to orange heulandite with a few scattered stilbite or calcite. The deep orange heulandite faded to light pink after removal from the damp rock.

Several large mud-filled pockets in the spillway were only lined with drusy quartz, mordenite, and a couple small stilbite crystals. One small opening in the floor of the spillway, when fully opened, exposed a snow-white lined pocket over 2 meter in diameter, lined with white quartz-mordenite with white scattered stilbite up to 6 cm long.

Later, after the dam was completed, the guard at the site was floating on the reservoir with a boat and found a large pocket of exceptional analcime in the north wall. Collecting during construction was extremely restricted to the geologist on the project, the guard at the dam, and a young geology student Rudy Tschernich. Collecting is now not allowed.

Rudy Tschernich

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


9 valid minerals.

Detailed Mineral List:

Analcime
Formula: Na(AlSi2O6) · H2O
Habit: trapazohedra to 7cm in diameter
Colour: colorless, transparent, translucent, white
'Apophyllite Group'
Formula: AB4[Si8O22]X · 8H2O
Habit: tetragonal bipyrmids to 1.5"
Colour: colorless to white
Calcite
Formula: CaCO3
Habit: scalenohedral crystals
Colour: yellow
'Chabazite'
Habit: crystals to 1/8"
Clinochlore
Formula: Mg5Al(AlSi3O10)(OH)8
'Heulandite Subgroup'
Formula: (Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
Laumontite
Formula: CaAl2Si4O12 · 4H2O
Mesolite
Formula: Na2Ca2Si9Al6O30 · 8H2O
Mordenite
Formula: (Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
Okenite
Formula: Ca10Si18O46 · 18H2O
Quartz
Formula: SiO2
'Stilbite Subgroup'
Formula: M6-7[Al8-9Si27-28O72] · nH2O
Thomsonite-Ca
Formula: NaCa2[Al5Si5O20] · 6H2O

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
Quartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
Calcite5.AB.05CaCO3
Group 9 - Silicates
Okenite9.EA.40Ca10Si18O46 · 18H2O
Clinochlore9.EC.55Mg5Al(AlSi3O10)(OH)8
Mesolite9.GA.05Na2Ca2Si9Al6O30 · 8H2O
Thomsonite-Ca9.GA.10NaCa2[Al5Si5O20] · 6H2O
Analcime9.GB.05Na(AlSi2O6) · H2O
Laumontite9.GB.10CaAl2Si4O12 · 4H2O
Mordenite9.GD.35(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
Unclassified
'Apophyllite Group'-AB4[Si8O22]X · 8H2O
'Chabazite'-
'Heulandite Subgroup'-(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
'Stilbite Subgroup'-M6-7[Al8-9Si27-28O72] · nH2O

List of minerals for each chemical element

HHydrogen
H AnalcimeNa(AlSi2O6) · H2O
H Apophyllite GroupAB4[Si8O22]X · 8H2O
H ClinochloreMg5Al(AlSi3O10)(OH)8
H Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
H LaumontiteCaAl2Si4O12 · 4H2O
H MesoliteNa2Ca2Si9Al6O30 · 8H2O
H Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
H OkeniteCa10Si18O46 · 18H2O
H Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
H Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
CCarbon
C CalciteCaCO3
OOxygen
O AnalcimeNa(AlSi2O6) · H2O
O Apophyllite GroupAB4[Si8O22]X · 8H2O
O CalciteCaCO3
O ClinochloreMg5Al(AlSi3O10)(OH)8
O Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
O LaumontiteCaAl2Si4O12 · 4H2O
O MesoliteNa2Ca2Si9Al6O30 · 8H2O
O Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
O OkeniteCa10Si18O46 · 18H2O
O QuartzSiO2
O Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
O Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
NaSodium
Na AnalcimeNa(AlSi2O6) · H2O
Na Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
Na MesoliteNa2Ca2Si9Al6O30 · 8H2O
Na Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
Na Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
MgMagnesium
Mg ClinochloreMg5Al(AlSi3O10)(OH)8
AlAluminium
Al AnalcimeNa(AlSi2O6) · H2O
Al ClinochloreMg5Al(AlSi3O10)(OH)8
Al Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
Al LaumontiteCaAl2Si4O12 · 4H2O
Al MesoliteNa2Ca2Si9Al6O30 · 8H2O
Al Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
Al Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
Al Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
SiSilicon
Si AnalcimeNa(AlSi2O6) · H2O
Si Apophyllite GroupAB4[Si8O22]X · 8H2O
Si ClinochloreMg5Al(AlSi3O10)(OH)8
Si Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
Si LaumontiteCaAl2Si4O12 · 4H2O
Si MesoliteNa2Ca2Si9Al6O30 · 8H2O
Si Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
Si OkeniteCa10Si18O46 · 18H2O
Si QuartzSiO2
Si Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
Si Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
KPotassium
K Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
K Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
CaCalcium
Ca CalciteCaCO3
Ca Heulandite Subgroup(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
Ca LaumontiteCaAl2Si4O12 · 4H2O
Ca MesoliteNa2Ca2Si9Al6O30 · 8H2O
Ca Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
Ca OkeniteCa10Si18O46 · 18H2O
Ca Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O

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