Parthasarathy, T.N., Parihar, P.S. & Krishna, K.V.G. 1990. Potash feldspar-rich alkaline rocks of Rangit Tectonic Window, south Sikkim: their genesis and relation to uranium, thorium, and REE mineralizations in the area. Exploration and Research for Atomic Minerals, 3, 115-130.

ⓘ 'Hornblende Root Name Group'

Formula: ◻Ca₂(Z²⁺₄Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

ⓘ Ilmenite

Formula: Fe²⁺TiO₃

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

References:

ⓘ Orthoclase

Formula: K(AlSi₃O₈)

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

References:

ⓘ 'Plagioclase'

Formula: (Na,Ca)[(Si,Al)AlSi₂]O₈

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

References:

ⓘ Quartz

Formula: SiO₂

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

References:

ⓘ Riebeckite

Formula: ◻[Na₂][Fe²⁺₃Fe³⁺₂]Si₈O₂₂(OH)₂

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

References:

ⓘ Rutile

Formula: TiO₂

Locality: Sikkim, Namchi, South Sikkim district, Sikkim, India

References:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘ	Ilmenite	4.CB.05	Fe²⁺TiO₃
ⓘ	Quartz	4.DA.05	SiO₂
ⓘ	Rutile	4.DB.05	TiO₂
Group 9 - Silicates
ⓘ	Aegirine	9.DA.25	NaFe³⁺Si₂O₆
ⓘ	Riebeckite	9.DE.25	◻[Na₂][Fe²⁺₃Fe³⁺₂]Si₈O₂₂(OH)₂
ⓘ	Orthoclase	9.FA.30	K(AlSi₃O₈)
Unclassified
ⓘ	'Hornblende Root Name Group'	-	◻Ca₂(Z²⁺₄Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
ⓘ	'Plagioclase'	-	(Na,Ca)[(Si,Al)AlSi₂]O₈

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Riebeckite	◻[Na₂][Fe₃²⁺Fe₂³⁺]Si₈O₂₂(OH)₂
H	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
O	Oxygen
O	ⓘ Aegirine	NaFe³⁺Si₂O₆
O	ⓘ Ilmenite	Fe²⁺TiO₃
O	ⓘ Orthoclase	K(AlSi₃O₈)
O	ⓘ Quartz	SiO₂
O	ⓘ Riebeckite	◻[Na₂][Fe₃²⁺Fe₂³⁺]Si₈O₂₂(OH)₂
O	ⓘ Rutile	TiO₂
O	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
O	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
F	Fluorine
F	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
Na	Sodium
Na	ⓘ Aegirine	NaFe³⁺Si₂O₆
Na	ⓘ Riebeckite	◻[Na₂][Fe₃²⁺Fe₂³⁺]Si₈O₂₂(OH)₂
Na	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Al	Aluminium
Al	ⓘ Orthoclase	K(AlSi₃O₈)
Al	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
Al	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	Silicon
Si	ⓘ Aegirine	NaFe³⁺Si₂O₆
Si	ⓘ Orthoclase	K(AlSi₃O₈)
Si	ⓘ Quartz	SiO₂
Si	ⓘ Riebeckite	◻[Na₂][Fe₃²⁺Fe₂³⁺]Si₈O₂₂(OH)₂
Si	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
Si	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Cl	Chlorine
Cl	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
K	Potassium
K	ⓘ Orthoclase	K(AlSi₃O₈)
Ca	Calcium
Ca	ⓘ Hornblende Root Name Group	◻Ca₂(Z₄²⁺Z³⁺)(AlSi₇O₂₂)(OH,F,Cl)₂
Ca	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Ti	Titanium
Ti	ⓘ Ilmenite	Fe²⁺TiO₃
Ti	ⓘ Rutile	TiO₂
Fe	Iron
Fe	ⓘ Aegirine	NaFe³⁺Si₂O₆
Fe	ⓘ Ilmenite	Fe²⁺TiO₃
Fe	ⓘ Riebeckite	◻[Na₂][Fe₃²⁺Fe₂³⁺]Si₈O₂₂(OH)₂

Geochronology

Mineralization age: Early/Lower Cretaceous : 121 Ma to 105 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

Phanerozoic

Mesozoic

Cretaceous

Early/Lower Cretaceous

ⓘ Peralkaline syenite (youngest age)	105 Ma	Sikkim, Namchi, South Sikkim district, Sikkim, India
ⓘ Peralkaline syenite (oldest age)	121 Ma	Sikkim, Namchi, South Sikkim district, Sikkim, India

Fossils

There are 2 fossil localities 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

296 Ma (Permian)

Oldest Fossil Listed

299 Ma (Carboniferous)

Fossils from Region

Click here to show the list.

Accepted Name	Hierarchy	Age
Syringothyris genus	Animalia : Brachiopoda : Rhynchonellata : Spiriferinida : Syringothyrididae : *Syringothyris*	298.9 - 295.5 Ma Paleozoic
Brachythyrinella papillionata species	Animalia : Brachiopoda : Rhynchonellata : Spiriferida : Trigonotretidae : Brachythyrinella : *Brachythyrinella papillionata*	298.9 - 295.5 Ma Paleozoic
Eurydesma mytiloides species	Animalia : Mollusca : Bivalvia : Pectinida : Chaenocardiidae : Eurydesma : *Eurydesma mytiloides*	298.9 - 295.5 Ma Paleozoic
Protoretepora ampla species	Animalia : Bryozoa : Stenolaemata : Fenestrida : Polyporidae : Protoretepora : *Protoretepora ampla*	298.9 - 295.5 Ma Paleozoic
Eurydesma subdepressa species	Animalia : Mollusca : Bivalvia : Myalinida : Myalinidae : Eurydesma : *Eurydesma subdepressa*	298.9 - 295.5 Ma Paleozoic
Eurydesma austini species	Animalia : Mollusca : Bivalvia : Myalinida : Myalinidae : Eurydesma : *Eurydesma austini*	298.9 - 295.5 Ma Paleozoic
Eurydesma subtriangularis species	Animalia : Mollusca : Bivalvia : Myalinida : Myalinidae : Eurydesma : *Eurydesma subtriangularis*	298.9 - 295.5 Ma Paleozoic
Ambikella fructiformis species	Animalia : Brachiopoda : Rhynchonellata : Spiriferida : Ingelarellidae : Ambikella : *Ambikella fructiformis*	298.9 - 295.5 Ma Paleozoic
Brachythyrinella duttai species	Animalia : Brachiopoda : Rhynchonellata : Spiriferida : Trigonotretidae : Brachythyrinella : *Brachythyrinella duttai*	298.9 - 295.5 Ma Paleozoic
Eurydesma cordatum species	Animalia : Mollusca : Bivalvia : Pectinida : Chaenocardiidae : Eurydesma : *Eurydesma cordatum*	298.9 - 295.5 Ma Paleozoic

Fossil Localities

Click to show 2 fossil localities

India

Sikkim
- Paleozoic🐚 Khemgaon Chorten
- Paleozoic🐚 Wak

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Namchi
Wikidata ID:	Q2483862
GeoNames ID:	1262029

Localities in this Region

India

Sikkim
- South Sikkim district
  - Namchi
    - Sikkim

Other Regions, Features and Areas that Intersect

Asia

HimalayasMountain Range
Hindukush Himalayan RegionGroup of Mountain Ranges

Eurasian PlateTectonic Plate

Himalayan Orogenic BeltOrogenic Belt

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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Namchi, South Sikkim district, Sikkim, IndiaiRegional Level TypesNamchiCity South Sikkim districtDistrict SikkimState IndiaCountry function showexplain() { $("#locexplain").toggle(); if (typeof movemap === "function") movemap(); }

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Detailed Mineral List:

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List of minerals arranged by Strunz 10th Edition classification

List of minerals for each chemical element

Geochronology

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Localities in this Region

Other Regions, Features and Areas that Intersect

Namchi, South Sikkim district, Sikkim, India i
Regional Level Types
Namchi City
South Sikkim district District
Sikkim State
India Country