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Main Crater, Iodake (Iwodake; Ioudake), Satsuma-Ioujima (Satsuma-Iwojima; Iou island), Mishima village, Kagoshima District, Kagoshima Prefecture, Japani
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Latitude & Longitude (WGS84):
30° 47' 29'' North , 130° 18' 29'' East
Latitude & Longitude (decimal):
Type:
Kรถppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Issล | 458 (2017) | 41.4km |
| Yoshida | 387 (2017) | 42.5km |
| Nagata | 1,192 (2017) | 45.4km |
| Miyanoura | 6,544 (2017) | 47.7km |
| Makurazaki | 24,971 (2017) | 52.8km |
Main crater of Iodake volcano, known for its high-temperature fumaroles.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsMineral List
30 valid minerals.
Rock Types Recorded
Note: data is currently VERY limited. Please bear with us while we work towards adding this information!
Select Rock List Type
Alphabetical List Tree DiagramDetailed Mineral List:
| โ Aegirine Formula: NaFe3+Si2O6 Description: Green to dark-green elongated, sometimes acicular crystals of good luster and well-developed crystal tips. Common in high-temperature fumaroles in the vicinity of halite crystals, in the hotter, central parts of the fumaroles. References: |
| โ Anglesite Formula: PbSO4 |
| โ Anhydrite Formula: CaSO4 Description: Furs of millimeter-sized white elongated crystals in crevices of a altered tephra. Associated with opal.
References: |
| โ Aphthitalite Formula: (K,Na)3Na(SO4)2 Habit: Massive crusts. Colour: Gray to black. Description: Solid gray to black crusts, water soluble. The dark color may be caused by finely dispersed molybdenite. Occurs in a zone where the bulk of the metal oxide and sulfide sublimates get deposited. Raman analysis of a black matrix with embedded tugarinovite crystals shows a curve that is a superposition of a molybdenite and aphthitalite patterns. Raman analysis done by Gรผnter Frenz.
References: |
| โ Cassiterite Formula: SnO2 |
| โ 'Clinopyroxene Subgroup' Colour: green Description: Green euhedral elongated crystals inside matrix of crumbly silicified rocks around high-temperature fumaroles.
SXRD by Uwe Kolitsch, NHM Vienna.
SXRD: C mon, 9.72, 8.89, 5.30, 106.6
Large diopside component.
References: |
| โ Clinosulphur Formula: S8 References: |
| โ 'Copiapite Group' Colour: olive-green
Description: Olive-green pustules on reddish, crumbly rocks at the surface of high-temperature fumaroles. Raman analysis by Gรผnter Frenz. References: |
| โ 'Coquimbite Group' Description: Sub-millimeter sized, yellow-white to white pustules, associated with copiapite at high-temperature fumaroles. Perhaps not formed as a sublimate but recrystallized from watery solutions of dissolved sublimates.
References: |
| โ Cotunnite Formula: PbCl2 |
| โ Cristobalite Formula: SiO2 |
| โ Ferberite Formula: FeWO4 |
| โ 'Garnet Group' Formula: X3Z2(SiO4)3 Habit: Equant habit, typical, well-developed garnet crystals. Rhombic dodecahedra {110}, sometimes modified by {211}. Colour: Orange, orange-yellow, green-brown. Description: Small orange, yellow-orange and green-brown clear crystals with good vitreous luster. Well-developed and typical garnet-like crystal-shape with rhombic dodecahedra {110}, sometimes modified by {211}. Identified by Raman spectroscopy.
Crystals occur in small groups inside high-temperature fumaroles associated with green pyroxenes. They can be seen in light-colored zones without sulfide and metal oxide sublimates.
Raman analysis by Gรผnter Frenz. References: |
| โ Gypsum Formula: CaSO4 · 2H2O Colour: Colorless or white, but also intensely colored yellow, green or blue by impurities like molybdenum blue. Description: Fibrous crusts in the vicinity of high temperature fumaroles. Colorless, white, but also colored yellow, green or blue (by molybdenum blue). References: |
| โ Halite Formula: NaCl Habit: Cubes, needles, blades, as well as massive with fibrous structure. Colour: colorless, sometimes gray and red by magnetite and hematite. Description: 1. As solid crusts of up to 1 cm thickness with fibrous fracture and smooth to cauliform surface inside high-temperature fumaroles. The crusts are clear with a dark blue tint when removed from inside the fumarole, but turn white upon shrinking and audibly cracking in ambient temperatures.
2. As white, millimeter-sized hopper-shaped cubes, mostly intergrown as little crystal trees, covering the inner walls of high-temperature fumaroles, also on solid halite crusts.
3. As long needles (up to several centimeters), randomly intergrown, inside large high-temperature fumaroles.
Description based on samples taken from fumaroles with 650 and 720 deg C on the northern inner wall of the crater (Amir Akhavan 2015, 2017).
References: |
| โ Hematite Formula: Fe2O3 |
| โ Hydroniumjarosite Formula: (H3O)Fe3+3(SO4)2(OH)6 |
| โ Ilsemannite Formula: Mo3O8 · nH2O Description: Conspicuous blue sublimates that cover whitish silicified rocks around high temperature fumaroles. Occasionally included in gypsum crusts, then dark blue-green. Most specimens are not stable and will pale. Molybdenum blue is water-soluble: after strong rain the blue sublimates around high-temperature fumaroles may be gone. References: |
| โ Jarosite Formula: KFe3+3(SO4)2(OH)6 |
| โ Magnetite Formula: Fe2+Fe3+2O4 Description: In and on salt crusts and halite cubes in high temperature fumaroles. Tiny octahedal crystals.
Also as tiny, black plates, associated with a red-brown, translucent mineral, possibly hematite. These crystals may look like iron roses, as if initially deposited hematite had been reduced to magnetite. Crystal flakes are attracted by a magnet, powder XRD confirms magnetite.
References: |
| โ Molybdenite Formula: MoS2 Description: Tiny, sub-millimeter sized, shiny flakes. Often embedded in silicified rocks around high-temperature fumaroles, but also as a sublimate in high-temperature fumaroles. Finely dispersed black powder in sulfate-crusts of high-temperature fumaroles.
|
| โ Molybdite Formula: MoO3 Colour: colorless to slightly blue, sometimes zoned Description: Elongated to stubby prismatic or platy crystals with striation along the elongated axis. Colorless or slightly blue, with submetallic to adamantine luster (vitreous luster at very high magnifications). Translucent to transparent. Crystals are very small but well visible as sparkling groups.
Identity of colorless crystals confirmed with SXRD by Jochen Schlรผter, University of Hamburg (aca).
|
| โ Native Sulphur Formula: S8 |
| โ Opal Formula: SiO2 · nH2O Description: Botryoidal, colorless hyalite, associated with sulfur, in and around low-temperature fumaroles. |
| โ Palmierite Formula: K2Pb(SO4)2 |
| โ Pyrite Formula: FeS2 |
| โ Quartz Formula: SiO2 Description: Common rock-forming mineral in highly silicified rocks close to high-temperature fumaroles.
Occasionally as a high-temperature fumarole sublimate in sub-millimeter sized, tapered, clear crystals, either as nests or single crystals.
|
| โ Sassolite Formula: H3BO3 Habit: Very thin and soft flakes. Description: Can be found close to the vents of small low temperature fumaroles in the vicinity of high-temperature fumaroles as a white sublimate. Water-soluble, hence can only be found after several days with dry weather.
|
| โ Sphalerite Formula: ZnS |
| โ 'Sulfurite' Formula: S Description: Small solidified sulfur flows (a few centimeters in length) of yellow, yellow-brown to orange color, close to fumaroles. References: |
| โ Sylvite Formula: KCl References: |
| โ Thรฉnardite Formula: Na2SO4 |
| โ Tridymite Formula: SiO2 |
| โ Tugarinovite Formula: MoO2 Description: Lilac-brown crystals of submetallic luster covering rocks in the immediate vicinity of high-temperature fumaroles. Also embedded in sulfate-crusts colored black by molybdenite. Crystal size well below 100 ยตm.
|
| โ 'Wollastonite Group' Habit: Acicular, in small radially grown tufts or randomly intergrown. Colour: Colorless Description: Colorless needles, in small tufts and randomly intergrown. Associated with garnet and green pyroxenes in high temperature fumaroles in zones with little or no metal sulfide sublimate deposition. Possibly (but not yet confirmed analytically) also on crumbly red rocks from high-temperature fumaroles associated with sulfates (copiapite group).
Raman analysis by Gรผnter Frenz. References: |
| โ Wulfenite Formula: Pb(MoO4) References: |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| โ | Clinosulphur | 1.CC. | S8 |
| โ | Native Sulphur | 1.CC.05 | S8 |
| Group 2 - Sulphides and Sulfosalts | |||
| โ | Sphalerite | 2.CB.05a | ZnS |
| โ | Molybdenite | 2.EA.30 | MoS2 |
| โ | Pyrite | 2.EB.05a | FeS2 |
| Group 3 - Halides | |||
| โ | Halite | 3.AA.20 | NaCl |
| โ | Sylvite | 3.AA.20 | KCl |
| โ | Cotunnite | 3.AB.85 | PbCl2 |
| Group 4 - Oxides and Hydroxides | |||
| โ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
| โ | Hematite | 4.CB.05 | Fe2O3 |
| โ | Quartz | 4.DA.05 | SiO2 |
| โ | Opal | 4.DA.10 | SiO2 ยท nH2O |
| โ | Tridymite | 4.DA.10 | SiO2 |
| โ | Cristobalite | 4.DA.15 | SiO2 |
| โ | Cassiterite | 4.DB.05 | SnO2 |
| โ | Tugarinovite | 4.DB.05 | MoO2 |
| โ | Ferberite | 4.DB.30 | FeWO4 |
| โ | Molybdite | 4.E0.10 | MoO3 |
| โ | Ilsemannite | 4.FJ.15 | Mo3O8 ยท nH2O |
| Group 6 - Borates | |||
| โ | Sassolite | 6.AA.05 | H3BO3 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| โ | Aphthitalite | 7.AC.35 | (K,Na)3Na(SO4)2 |
| โ | Thรฉnardite | 7.AD.25 | Na2SO4 |
| โ | Anhydrite | 7.AD.30 | CaSO4 |
| โ | Anglesite | 7.AD.35 | PbSO4 |
| โ | Palmierite | 7.AD.40 | K2Pb(SO4)2 |
| โ | Hydroniumjarosite | 7.BC.10 | (H3O)Fe3+3(SO4)2(OH)6 |
| โ | Jarosite | 7.BC.10 | KFe3+3(SO4)2(OH)6 |
| โ | Gypsum | 7.CD.40 | CaSO4 ยท 2H2O |
| โ | Wulfenite | 7.GA.05 | Pb(MoO4) |
| Group 9 - Silicates | |||
| โ | Aegirine | 9.DA.25 | NaFe3+Si2O6 |
| Unclassified | |||
| โ | 'Clinopyroxene Subgroup' | - | |
| โ | 'Garnet Group' | - | X3Z2(SiO4)3 |
| โ | 'Copiapite Group' | - | |
| โ | 'Sulfurite' | - | S |
| โ | 'Wollastonite Group' | - | |
| โ | 'Coquimbite Group' | - | |
List of minerals for each chemical element
Other Regions, Features and Areas containing this locality
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Main Crater, Iodake, Satsuma-Ioujima, Mishima village, Kagoshima District, Kagoshima Prefecture, Japan