Planetary Simulant Database: IRS-1 Itokawa Regolith Simulant

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Mineral Wt %
Olivine (Fo91.6</sub) 60
Orthopyroxene (En69.3Wo1.2) 20
Clinopyroxene (En40.5Wo44.8) 5
Plagioclase (Albite, Ab95.2) 10
Pyrrhotine 3
Iron filings 2

Bulk Chemistry

Oxide Wt.%
SiO2 42.7
TiO2 0.44
Al2O3 3.40
Cr2O3 0.05
FeO/Fe2O3 15.8
MnO 0.16
MgO 34.3
CaO 1.47
Na2O 1.06
K2O 0.04
P2O5 0.05
Total 99.4

Physical Properties

Property Value
Bulk density 1.62 g/cm3
Specific gravity 3.37 g/cm3
Cohesion 10 kPa
Angle of friction 46.8°
Simulant Name: IRS-1 Itokawa Regolith Simulant
Current Status: Available for request
Developed By: Chinese Academy of Sciences
Available From: Xiaojia Zeng ( or Xiongyao Li (
Publications: Zeng, X. et al. (2019), The Itokawa regolith simulant IRS-1 as an S-type asteroid surface analogue. Icarus, accepted

IRS-1 was developed to support China’s upcoming asteroid missions. It is a general purpose simulant designed to match the composition and physical properties of the S-type asteroid Itokawa, based on analysis of returned samples.


Photograph of the inputs and the final simulant, reproduced from Fig. 1 in Zeng et al., accepted.