Actinolite : CSIRO Spectroscopy Database

Actinolite [ ☐Ca₂(Mg_4.5-2.5Fe^II_0.5-2.5)Si₈O₂₂(OH)₂ ]

Image of Actinolite

Actinolite specimen from White River, Wenatchee National Forest, WA, USA

Photo by Penland, via Smithsonian National Museum of Natural History

Material properties

Formula	☐Ca₂(Mg_4.5-2.5Fe^II_0.5-2.5)Si₈O₂₂(OH)₂
Abbreviation	Act
Classifications	Minerals containing OH, Actinolite root name group, Ferro-actinolite-Tremolite (series)
Luminescence emitters	Cr, Mn
Spectra	Reflectance (2)
IMA Status	Approved/redefined (IMA 2012 s.p.)
Search other databases	webmineral.com, mindat.org, rruf.info, fluomin.org, mineralienatlas.de, Handbook of Mineralogy, American Mineralogist Crystal Structure Database
Crystal symmetry	Monoclinic, Point group 2/m, Space group C2/m (#12)
Tags	Mineral, Silicate , Hydroxide

Composition

Element	Wt%
H	0.24
Na	0.59
Mg	9.71
Ca	8.6
Ti	0.11
Mn	0.13
Fe	8.58
Al	1.39
Si	25.64
O	45.01
Total:	100

References for Actinolite

Bakhtin 1985

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Bakhtin & Moroshkin 1986

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Pejcic et al. 2022 (EP2022-5804)

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Pejcic et al. 2021 (EP2021-1148)

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Specimens of Actinolite

Name	Owner	Materials	Phase purity	Image	Spectra	Techniques
NR-ACT-02 Actinolite	CSIRO	Actinolite (89.3%), Clinochlore, Fe, Magnetite, Quartz, Tremolite	89.3	NR-ACT-02 Actinolite Image of Actinolite, Clinochlore (var. Fe), Magnetite, Quartz and Tremolite in specimen 'NR-ACT-02 Actinolite' [CSIRO]. (C) 2025 CSIRO Mineral Resources. All rights reserved.	2	Reflectance
M1063 Scheelite / Actinolite	CSIRO	Actinolite (34.3%), Albite, Ca, Scheelite	34.3	M1063 Scheelite / Actinolite Image of Scheelite, Actinolite and Albite (var. Ca) in specimen 'M1063 Scheelite / Actinolite' [CSIRO]. (C) 2026 CSIRO Mineral Resources. All rights reserved.	0	—
MES177 Tremolite / Actinolite	NVCL, AuScope Limited	Actinolite (27.2%), Clinochlore, Fe, Quartz, Tremolite	27.2	MES177 Tremolite / Actinolite Image of Actinolite, Clinochlore (var. Fe), Quartz and Tremolite in specimen 'MES177 Tremolite / Actinolite' [NVCL, AuScope Limited], from Spoo Ness, Lunda Wick, Unst, Shetland Islands, United Kingdom. (C) 2026 CSIRO Mineral Resources. All rights reserved.	2	Reflectance
MES082 Omphacite / Ferro-glaucophane / Epidote	CSIRO	Actinolite (8.0%), Albite, Calcite, Epidote, Ferro-glaucophane, Majorite, Omphacite, Quartz, Titanite	8.0	MES082 Omphacite / Ferro-glaucophane / Epidote Image of Omphacite, Actinolite, Albite, Calcite, Epidote, Ferro-glaucophane, Majorite, Quartz and Titanite in specimen 'MES082 Omphacite / Ferro-glaucophane / Epidote' [CSIRO]. (C) 2026 CSIRO Mineral Resources. All rights reserved.	0	—
M0732 Magnetite	CSIRO	Actinolite (3.2%), Cummingtonite, Fe2+, Magnetite	3.2	M0732 Magnetite Image of Magnetite, Actinolite and Cummingtonite (var. Fe2+) in specimen 'M0732 Magnetite' [CSIRO]. (C) 2026 CSIRO Mineral Resources. All rights reserved.	0	—
MES181 Scheelite	CSIRO	Actinolite (1.9%), Scheelite	1.9	MES181 Scheelite Image of Scheelite and Actinolite in specimen 'MES181 Scheelite' [CSIRO], from Bispbergs Klack, Säter Municipality, Dalarna, Sweden. (C) 2026 CSIRO Mineral Resources. All rights reserved.	1	Reflectance
M1064 Scheelite	CSIRO	Actinolite (1.7%), Scheelite	1.7	M1064 Scheelite Image of Scheelite and Actinolite in specimen 'M1064 Scheelite' [CSIRO], from Queensland, Australia. (C) 2026 CSIRO Mineral Resources. All rights reserved.	2	Reflectance