Island group west of Outer Hebrides; Tertiary Intrusive complex. Permission for access must be obtained from the Nature Conservancy and the National Trust for Scotland before visiting the islands.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List

Mineral list contains entries from the region specified including sub-localities

ⓘ 'Allanite Group'

ⓘ 'Amphibole Supergroup'

ⓘ 'Fayalite-Forsterite Series'

ⓘ 'Orthopyroxene Subgroup'

16 valid minerals.

Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

Rock list contains entries from the region specified including sub-localities

Select Rock List Type

Alphabetical List Tree Diagram

ⓘ Andesite

ⓘ Basalt

ⓘ 'Bytownite olivine-gabbro'

ⓘ 'Granophyric granite'

ⓘ 'Intrusive breccia'

Entries shown in red are rocks recorded for this region.

Igneous rock
- Normal crystalline igneous rock

Detailed Mineral List:

ⓘ 'Allanite Group'

Formula: (A1²⁺REE³⁺)(M1³⁺M2³⁺M3²⁺)O[Si₂O₇][SiO₄](OH)

References:

Harding, R. R., Merriman, R. J., Nancarrow, P. H. A. (1982) A note on the occurrence of chevkinite, allanite, and zirkelite on St. Kilda, Scotland. Mineralogical Magazine, 46 (341) 445-448 doi:10.1180/minmag.1982.046.341.06

ⓘ 'Amphibole Supergroup'

Formula: AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Anatase

Formula: TiO₂

Habit: tabular

Colour: dark green

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Anorthite

Formula: Ca(Al₂Si₂O₈)

Locality: Hirta, St Kilda, Outer Hebrides, Scotland, UK

References:

Miller, J. A., & Mohr, P. A. (1965). Potassium-argon age determinations on rocks from St Kilda and Rockall. Scottish Journal of Geology, 1(1), 93-99.

ⓘ Anorthite var. Bytownite

Formula: (Ca,Na)[Al(Al,Si)Si₂O₈]

Locality: Hirta, St Kilda, Outer Hebrides, Scotland, UK

References:

Miller, J. A., & Mohr, P. A. (1965). Potassium-argon age determinations on rocks from St Kilda and Rockall. Scottish Journal of Geology, 1(1), 93-99.

ⓘ Augite

Formula: (Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ 'Biotite'

Formula: K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ 'Chabazite'

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

ⓘ Chevkinite-(Ce)

Formula: Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂

Habit: prismatic to acicular, up to 0.2mm

Colour: Red-brown (pleochroic) in thin section; appears black and near-opaque in hand specimens

Description: First British occurrence for this species. Mostly observed in thin sections. Can be seen with x10 loupe in hand specimens, but easily mistaken for amphibole or edge-views of dark mica (although the latter is almost absent in most of the chevkinite-bearing rocks of St Kilda). Red haloes are commonly seen around specimens in the Conachair granite.

References:

ⓘ Epidote

Formula: (CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

ⓘ 'Fayalite-Forsterite Series'

Localities:

St Kilda, Outer Hebrides, Scotland, UK
Hirta, St Kilda, Outer Hebrides, Scotland, UK

ⓘ 'Feldspar Group'

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Fluorite

Formula: CaF₂

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Magnetite

Formula: Fe²⁺Fe³⁺₂O₄

Habit: octaheda & massive (rock-forming)

Colour: black

Description: Magnetite is abundant as a rock-forming component in the basic rocks of St Kilda, and is also common as sharply euhedral lustrous octahedra in vugs in the Conachair Granite.

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Orthoclase

Formula: K(AlSi₃O₈)

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

ⓘ 'Orthopyroxene Subgroup'

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ 'Plagioclase'

Formula: (Na,Ca)[(Si,Al)AlSi₂]O₈

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Prehnite

Formula: Ca₂Al₂Si₃O₁₀(OH)₂

References:

Harding R.R., Merriman R.J. and Nancarrow P.H.A. 1984. St Kilda: an illustrated account of the geology. Rep. British Geological Survey, vol. 16 no 7

ⓘ Quartz

Formula: SiO₂

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Rutile

Formula: TiO₂

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Scolecite

Formula: CaAl₂Si₃O₁₀ · 3H₂O

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

ⓘ 'Silica'

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Spinel

Formula: MgAl₂O₄

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Titanite

Formula: CaTi(SiO₄)O

References:

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Zircon

Formula: Zr(SiO₄)

References:

St Kilda: an Illustrated Account of the Geology. Harding R.R., Merriman R.J. & Nancarrow P.H.A. 1984 (British Geological Survey Report Vol 16, No 7)

www.kilda.org.uk (2003) http://www.kilda.org.uk/kildanomdoc/level3p1.htm

ⓘ Zirkelite

Formula: (Ti,Ca,Zr)O_2-x

References:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 3 - Halides
ⓘ	Fluorite	3.AB.25	CaF₂
Group 4 - Oxides and Hydroxides
ⓘ	Magnetite	4.BB.05	Fe²⁺Fe³⁺₂O₄
ⓘ	Spinel	4.BB.05	MgAl₂O₄
ⓘ	Quartz	4.DA.05	SiO₂
ⓘ	Rutile	4.DB.05	TiO₂
ⓘ	Anatase	4.DD.05	TiO₂
ⓘ	Zirkelite	4.DL.05	(Ti,Ca,Zr)O_2-x
Group 9 - Silicates
ⓘ	Zircon	9.AD.30	Zr(SiO₄)
ⓘ	Titanite	9.AG.15	CaTi(SiO₄)O
ⓘ	Chevkinite-(Ce)	9.BE.70	Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂
ⓘ	Epidote	9.BG.05a	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
ⓘ	Augite	9.DA.15	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
ⓘ	Prehnite	9.DP.20	Ca₂Al₂Si₃O₁₀(OH)₂
ⓘ	Orthoclase	9.FA.30	K(AlSi₃O₈)
ⓘ	Anorthite	9.FA.35	Ca(Al₂Si₂O₈)
ⓘ	var. Bytownite	9.FA.35	(Ca,Na)[Al(Al,Si)Si₂O₈]
ⓘ	Scolecite	9.GA.05	CaAl₂Si₃O₁₀ · 3H₂O
Unclassified
ⓘ	'Amphibole Supergroup'	-	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
ⓘ	'Biotite'	-	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
ⓘ	'Chabazite'	-
ⓘ	'Feldspar Group'	-
ⓘ	'Fayalite-Forsterite Series'	-
ⓘ	'Plagioclase'	-	(Na,Ca)[(Si,Al)AlSi₂]O₈
ⓘ	'Silica'	-
ⓘ	'Orthopyroxene Subgroup'	-
ⓘ	'Allanite Group'	-	(A1²⁺REE³⁺)(M1³⁺M2³⁺M3²⁺)O[Si₂O₇][SiO₄](OH)

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
H	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
H	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
H	ⓘ Prehnite	Ca₂Al₂Si₃O₁₀(OH)₂
H	ⓘ Scolecite	CaAl₂Si₃O₁₀ · 3H₂O
H	ⓘ Allanite Group	(A1²⁺REE³⁺)(M1³⁺M2³⁺M3²⁺)O[Si₂O₇][SiO₄](OH)
O	Oxygen
O	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
O	ⓘ Anatase	TiO₂
O	ⓘ Anorthite	Ca(Al₂Si₂O₈)
O	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
O	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
O	ⓘ Anorthite var. Bytownite	(Ca,Na)[Al(Al,Si)Si₂O₈]
O	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
O	ⓘ Magnetite	Fe²⁺Fe₂³⁺O₄
O	ⓘ Orthoclase	K(AlSi₃O₈)
O	ⓘ Prehnite	Ca₂Al₂Si₃O₁₀(OH)₂
O	ⓘ Quartz	SiO₂
O	ⓘ Rutile	TiO₂
O	ⓘ Scolecite	CaAl₂Si₃O₁₀ · 3H₂O
O	ⓘ Spinel	MgAl₂O₄
O	ⓘ Titanite	CaTi(SiO₄)O
O	ⓘ Zircon	Zr(SiO₄)
O	ⓘ Zirkelite	(Ti,Ca,Zr)O_2-x
O	ⓘ Chevkinite-(Ce)	Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂
O	ⓘ Fayalite-Forsterite Series
O	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
O	ⓘ Allanite Group	(A1²⁺REE³⁺)(M1³⁺M2³⁺M3²⁺)O[Si₂O₇][SiO₄](OH)
F	Fluorine
F	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
F	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
F	ⓘ Fluorite	CaF₂
Na	Sodium
Na	ⓘ Anorthite var. Bytownite	(Ca,Na)[Al(Al,Si)Si₂O₈]
Na	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Mg	Magnesium
Mg	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Mg	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Mg	ⓘ Spinel	MgAl₂O₄
Mg	ⓘ Fayalite-Forsterite Series
Al	Aluminium
Al	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
Al	ⓘ Anorthite	Ca(Al₂Si₂O₈)
Al	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Al	ⓘ Anorthite var. Bytownite	(Ca,Na)[Al(Al,Si)Si₂O₈]
Al	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Al	ⓘ Orthoclase	K(AlSi₃O₈)
Al	ⓘ Prehnite	Ca₂Al₂Si₃O₁₀(OH)₂
Al	ⓘ Scolecite	CaAl₂Si₃O₁₀ · 3H₂O
Al	ⓘ Spinel	MgAl₂O₄
Al	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	Silicon
Si	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
Si	ⓘ Anorthite	Ca(Al₂Si₂O₈)
Si	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Si	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Si	ⓘ Anorthite var. Bytownite	(Ca,Na)[Al(Al,Si)Si₂O₈]
Si	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Si	ⓘ Orthoclase	K(AlSi₃O₈)
Si	ⓘ Prehnite	Ca₂Al₂Si₃O₁₀(OH)₂
Si	ⓘ Quartz	SiO₂
Si	ⓘ Scolecite	CaAl₂Si₃O₁₀ · 3H₂O
Si	ⓘ Titanite	CaTi(SiO₄)O
Si	ⓘ Zircon	Zr(SiO₄)
Si	ⓘ Chevkinite-(Ce)	Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂
Si	ⓘ Fayalite-Forsterite Series
Si	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	ⓘ Allanite Group	(A1²⁺REE³⁺)(M1³⁺M2³⁺M3²⁺)O[Si₂O₇][SiO₄](OH)
Cl	Chlorine
Cl	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
K	Potassium
K	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
K	ⓘ Orthoclase	K(AlSi₃O₈)
Ca	Calcium
Ca	ⓘ Anorthite	Ca(Al₂Si₂O₈)
Ca	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Ca	ⓘ Anorthite var. Bytownite	(Ca,Na)[Al(Al,Si)Si₂O₈]
Ca	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Ca	ⓘ Fluorite	CaF₂
Ca	ⓘ Prehnite	Ca₂Al₂Si₃O₁₀(OH)₂
Ca	ⓘ Scolecite	CaAl₂Si₃O₁₀ · 3H₂O
Ca	ⓘ Titanite	CaTi(SiO₄)O
Ca	ⓘ Zirkelite	(Ti,Ca,Zr)O_2-x
Ca	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Ti	Titanium
Ti	ⓘ Amphibole Supergroup	AB₂C₅((Si,Al,Ti)₈O₂₂)(OH,F,Cl,O)₂
Ti	ⓘ Anatase	TiO₂
Ti	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Ti	ⓘ Rutile	TiO₂
Ti	ⓘ Titanite	CaTi(SiO₄)O
Ti	ⓘ Zirkelite	(Ti,Ca,Zr)O_2-x
Ti	ⓘ Chevkinite-(Ce)	Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂
Fe	Iron
Fe	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Fe	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Fe	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Fe	ⓘ Magnetite	Fe²⁺Fe₂³⁺O₄
Fe	ⓘ Chevkinite-(Ce)	Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂
Fe	ⓘ Fayalite-Forsterite Series
Zr	Zirconium
Zr	ⓘ Zircon	Zr(SiO₄)
Zr	ⓘ Zirkelite	(Ti,Ca,Zr)O_2-x
Ce	Cerium
Ce	ⓘ Chevkinite-(Ce)	Ce₄(Ti,Fe²⁺,Fe³⁺)₅O₈(Si₂O₇)₂

Geochronology

Mineralization age: Paleocene : 60 ± 10 Ma to 57 ± 3 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic Time

Rocks, Minerals and Events

ⓘ Granophyric granite	57 ± 3 Ma	Hirta, St Kilda, Outer Hebrides, Scotland, UK
ⓘ Olivine dolerite	60 ± 10 Ma	Hirta, St Kilda, Outer Hebrides, Scotland, UK
ⓘ Basalt	60 ± 10 Ma	Hirta, St Kilda, Outer Hebrides, Scotland, UK

Fossils

There are 1 fossil locality from the PaleoBioDB database within this region.

These data are provided on an experimental basis and are taken from external databases. Mindat.org has no control currently over the accuracy of these data.

Occurrences

Youngest Fossil Listed

Oldest Fossil Listed

0.01 Ma (Pleistocene)

Fossils from Region

Click here to show the list.

Accepted Name	Hierarchy	Age
👁 Image Pinguinus impennis species	Animalia : Chordata : Aves : Charadriiformes : Alcidae : Pinguinus : *Pinguinus impennis*	0.0117 - 0 Ma Quaternary

Fossil Localities

Click to show 1 fossil locality

Scotland
- Outer Hebrides
  - St Kilda
    - Hirta
      - Quaternary🐚 St. Kilda

Localities in this Region

Scotland
- Outer Hebrides
  - St Kilda
    - ⭔Boreray
    - ⭔Hirta

Other Regions, Features and Areas that Intersect

Atlantic OceanOcean

British and Irish IslesGroup of Islands

Eurasian PlateTectonic Plate

Laurentia ProvinceCraton

North Atlantic Igneous ProvinceLarge Igneous Province

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.

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