A new mineral with the following formula is described: (K_1.788Na_0.148 Rb_0.141)(Li_2.536Mn²⁺_0.985Fe²⁺_0.183Fe³⁺_0.061Al_1.958Ti_0.012) (Si_6.646 Al_1.354)·O_19.634 (F_3.159 (OH)_1.202)=(K, Na, Rb)_2.077(Li, Mn, Fe²⁺, Fe³⁺, Al, Ti)_5.735(Si, Al)_8.000·O_19.639 (F, OH)_4.361 as OH+O+F=24. It corresponds to manganese analogue of zinnwaldite and is expressed by a K₂(Mn²⁺₂₋₁Li₂₋₃Al₂) (Al₂₋₁Si₆₋₇O₂₀) (F₂₋₃ (OH)₁₋₂). The name masutomilite is proposed for the material with Mn²⁺> Fe²⁺ in honor of Dr. Kazunosuke Masutomi for his contribution to minerals of Japan.
X-ray powder diffraction and optical data indicate the mineral to be monoclinic, space group Cm or C2⁄m with a 5.253(8)Å, b 9.085(4)Å, c 10.108(8)Å, β 100.15(0.03)°, V 474.84(0.56)ų and Z=1. The precession method verified the space group. The strongest lines in the X-ray powder pattern are 10.10(72)(001), 3.64(43)(-112), 3.32(100)(003), 3.09(58)(112), 2.903(35)(-113, 031), 2.589(17)(200, -131), 1.989(46)(005), 1.653(23)(204, -135). It is pale purplish pink. Transparent. Cleavage {001} perfect. Hardness (Mohs) 2.5. Sp. Gr. (meas.) 2.94 and 2.96 (calc). Optically biaxial negative with α 1.534, β 1.569, γ 1.570, (−)2V 29°–31°, r>v very weak, X, Z colorless to pale purple, Y purple, absorption X<Z<Y. Optical orientation b=Y, X nearly perpendicular to (001), a∧Z 3°.
The mineral occupies core part of a zoned single mica crystal up to 10 cm across and 1 cm thick found in a druse of granite pegmatite at Tanakamiyama, Otsu, Shiga Prefecture, Japan. The outer part of the crystal is a brown manganoan zinnwaldite. The associated minerals are topaz, schorl, albite and quartz.
For comparison of a high manganese zinnwaldite with masutomilite, a mica from Tawara, Naégi district, Hirukawa-mura, Gifu Prefecture, Japan is also described.
A complete solid solubility does exist for the masutomilite–lepidolite–zinnwaldite series. The relationship between chemical composition, unit-cell dimensions a or b, and optical properties for the masutomilite–lepidolite series is figured out.

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Sugilite occurs as an essential mineral amounting to 3–8 percent by volume in aegirine syenite from Iwagi Islet, Ehime Prefecture. It is associated with albite, aegirine, pectolite and a Ca-K-Ti silicate (a still to be identified mineral). Sugilite is light brownish yellow, luster vitreous, streak white. Symmetry hexagonal. Cleavage 0001 weak. Hardness 6–6¹/₂. Specific gravity 2.80₂ (calc.), 2.74 (meas.).
Under the microscope, it is uniaxial negative with ε=1.607, ω=1.610, ω−ε=0.003, and colorless.
Estimated chemical composition is SiO₂ 71.38, TiO₂ 0.51, A1₂O₃ 2.97, Fe₂O₃ 12.76, FeO 0.19, Li₂O 3.14, Na₂O 4.37, K₂O 3.76, H₂O(+) 0.81, H₂O(−) 0.12, total 100.01%, corresponding ideally to (K, Na)((H₂O), Na)₂(Fe³⁺, Na, Ti, Fe²⁺)₂(Li, Al, Fe³⁺)₃(Si₁₂O₃₀) with Z=2.
The unit cell dimensions are a₀=10.007(2), c₀=14.000(2)Å. Space group D²_6h−P6⁄mcc. X-ray powder data resemble those for sodgianite, milarite, osumilite, merrihueite, roedderite and brannockite.
It is clear from the above-cited data that sugilite has milarite-type structure and resembles sodgianite and brannockite in containing lithium in tetrahedral site, but it is distinguished by a high content of ferric iron in 6-coordination.
The name is given in honour of the late Professor Ken-ichi Sugi (1901-1948), who first found the occurrence of this mineral with Mr. M. Kutsuna.

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The solubility of alumina in orthopyroxene coexisting with spinel and forsterite has been discussed using a simple mixing model of orthopyroxene and it was revealed that the recent experimental results in MgO–Al₂O₃–SiO₂ system (MacGregor, 1974) do not agree with the model. Reexamination of the system gave the results which are in good agreement with thermodynamically calculated alumina solubility in orthopyroxene and indicated that, in the spinel-stability field, it is not sensitive to pressure.

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The applicability of X-ray photoelectron spectroscopy to the determination of the oxidation state of vanadium in minerals is studied. Using this technique, vanadium-rich aegirine (Na, Ca) (Fe, V)Si₂O₆ is found to contain vanadium as trivalent state.

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X-ray photoelectron spectroscopy has been used to determine the oxidation state of copper in various kinds of copper minerals. Cuprite Cu₂O is found to be stable to air oxidation. Photoelectron spectra of carrollite Co₂CuS₄, germanite Cu₃(Ge, Fe) (S, As)₄ and covelline CuS reveal that these minerals contain univalent copper.

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