Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Denny Gulch, Denny Mountain, Snoqualmie Mining District, King County, Washington, USAi
Regional Level Types
Denny GulchMine
Denny MountainMountain
Snoqualmie Mining DistrictMining District
King CountyCounty (Historical)
WashingtonState
USACountry

This page is currently not sponsored. Click here to sponsor this page.
PhotosMapsSearchMineralogy
Latitude & Longitude (WGS84):
47° 25' 44'' North , 121° 26' 59'' West
Latitude & Longitude (decimal):
Type:
Nearest Settlements:
PlacePopulationDistance
Snoqualmie Pass311 (2011)5.5km
Tanner1,018 (2011)22.9km
Riverbend2,132 (2011)23.0km
Wilderness Rim1,523 (2017)24.0km
North Bend6,679 (2017)26.4km
Mindat Locality ID:
10550
Long-form identifier:
mindat:1:2:10550:2
GUID (UUID V4):
0
Other/historical names associated with this locality:
Denny Mine; Denny Company Mine; Denny Creek; Rockhound Gulch


The canyon off of Denny Creek affectionately known as "Rockhound gulch" is one of the more well known mineral collecting localities in Washington. It is a skarn formed by the intrusion of the snoqualmie batholith into sedimentary rocks.


To reach Rockhound Gulch, take the Melakwa Lakes trail no. 1014. You will start on the west side of Denny Creek, cross to the east side via a large hewn log bridge, cross back to the west side where the trail descends a bank to a rock crossing. After this second crossing, the trail switchbacks up a hill, then comes back close to the creek canyon. At this point you will have a wide view of the cliffs of Low Mountain (5000 feet) on your left. Just after you see this view, the trail turns left, and a poor trial goes off the right side down into Denny Creek canyon, across a flat rock outcrop above a waterfall, to a rocky-bottomed canyon up the side of Denny Mountain. This is Rockhound Gulch.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


12 valid minerals. 1 erroneous literature entry.

Detailed Mineral List:

'Amphibole Supergroup'
Formula: AB2C5(T8O22)W2
'Amphibole Supergroup var. Byssolite'
Formula: AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Calcite
Formula: CaCO3
'Chlorite Group'
Chrysocolla
Formula: Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
Diopside
Formula: CaMgSi2O6
Habit: blocky crystals to .75 inches
Colour: greenish
Epidote
Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Habit: crystal sprays
Colour: dark Green
Goethite
Formula: Fe3+O(OH)
Grossular
Formula: Ca3Al2(SiO4)3
Hematite
Formula: Fe2O3
Habit: specular
Description: Forms platy aggregates, sometimes as terminated rosettes. Often, entire pockets are filled with hematite.
'K Feldspar'
'K Feldspar var. Adularia'
Formula: KAlSi3O8
Lepidocrocite
Formula: Fe3+O(OH)
Description: The strawberry and black inclusions in the amethyst scepters are hematite. No lepidocrocite has ever been found here.
Malachite
Formula: Cu2(CO3)(OH)2
Opal
Formula: SiO2 · nH2O
Pyrite
Formula: FeS2
Description: Occurs (rarely) as unoxidized cubes, but more commonly as goethite pseudomorphs.
Quartz
Formula: SiO2
Habit: Frequent Normal Prisms some with heamtite inclusions to a few cm. Spectacular large rare Japanese Twins to over 30 cm ear to ear
Colour: colourles to red from inclusions
Fluorescence: none
Description: The normal prisms are common but not the killer twins
Quartz var. Amethyst
Formula: SiO2
Habit: doubly terminated scepters on clear quartz prisms to a few cm
Colour: strawberry purple
Description: Hematite inclusions in the Amethyst give the strawberry colour.
References:
Scheelite
Formula: Ca(WO4)

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Pyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
Goethite4.00.Fe3+O(OH)
Hematite4.CB.05Fe2O3
Quartz
var. Amethyst
4.DA.05SiO2
4.DA.05SiO2
Opal4.DA.10SiO2 · nH2O
Lepidocrocite ?4.FE.15Fe3+O(OH)
Group 5 - Nitrates and Carbonates
Calcite5.AB.05CaCO3
Malachite5.BA.10Cu2(CO3)(OH)2
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
Scheelite7.GA.05Ca(WO4)
Group 9 - Silicates
Grossular9.AD.25Ca3Al2(SiO4)3
Epidote9.BG.05a(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Diopside9.DA.15CaMgSi2O6
Chrysocolla9.ED.20Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
Unclassified
'K Feldspar
var. Adularia'
-KAlSi3O8
'Amphibole Supergroup'-AB2C5(T8O22)W2
'Chlorite Group'-
'K Feldspar'-
'Amphibole Supergroup
var. Byssolite'
-AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2

List of minerals for each chemical element

HHydrogen
H ChrysocollaCu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
H Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
H GoethiteFe3+O(OH)
H LepidocrociteFe3+O(OH)
H MalachiteCu2(CO3)(OH)2
H OpalSiO2 · nH2O
H Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
CCarbon
C CalciteCaCO3
C MalachiteCu2(CO3)(OH)2
OOxygen
O K Feldspar var. AdulariaKAlSi3O8
O Quartz var. AmethystSiO2
O Amphibole SupergroupAB2C5(T8O22)W2
O CalciteCaCO3
O ChrysocollaCu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
O DiopsideCaMgSi2O6
O Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
O GoethiteFe3+O(OH)
O GrossularCa3Al2(SiO4)3
O HematiteFe2O3
O LepidocrociteFe3+O(OH)
O MalachiteCu2(CO3)(OH)2
O OpalSiO2 · nH2O
O QuartzSiO2
O ScheeliteCa(WO4)
O Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
FFluorine
F Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
MgMagnesium
Mg DiopsideCaMgSi2O6
AlAluminium
Al K Feldspar var. AdulariaKAlSi3O8
Al ChrysocollaCu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
Al Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Al GrossularCa3Al2(SiO4)3
Al Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
SiSilicon
Si K Feldspar var. AdulariaKAlSi3O8
Si Quartz var. AmethystSiO2
Si ChrysocollaCu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
Si DiopsideCaMgSi2O6
Si Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Si GrossularCa3Al2(SiO4)3
Si OpalSiO2 · nH2O
Si QuartzSiO2
Si Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
SSulfur
S PyriteFeS2
ClChlorine
Cl Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
KPotassium
K K Feldspar var. AdulariaKAlSi3O8
CaCalcium
Ca CalciteCaCO3
Ca DiopsideCaMgSi2O6
Ca Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Ca GrossularCa3Al2(SiO4)3
Ca ScheeliteCa(WO4)
TiTitanium
Ti Amphibole Supergroup var. ByssoliteAX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
FeIron
Fe Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Fe GoethiteFe3+O(OH)
Fe HematiteFe2O3
Fe LepidocrociteFe3+O(OH)
Fe PyriteFeS2
CuCopper
Cu ChrysocollaCu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
Cu MalachiteCu2(CO3)(OH)2
WTungsten
W ScheeliteCa(WO4)

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: September 3, 2026 13:42:54 Page updated: July 23, 2026 14:24:00
Go to top of page