Horváth Géza (szerk.): A Magyar Természettudományi Múzeum évkönyve 22. (Budapest 1925)

Koch, S.: Újabb előfordulású wolframit-kristályok Felsőbányáról

a {100} k {502} b {010} f {011} m {110} a {121} d {310} o {111} t {102} e {121} i {403} * {614} The general shape of this crystal is the same as that of the former one, and the appearance of the common faces are likewise similar. Interesting is m in the prismatic zone, for this form though often met with on crystals from other localities but on those of Felsőbánya are only very rarely. KRENNER did not find any and myself only on this one as a thin, bright streak. The small stripe of t as the trapez shaped faces of i like all domes of that zone are uneven and not very bright, o and e, on the contrary, are even, bright pyramids. There is also a negativ pyramids with steep, bad reflecting, dull face whose index I calculated by approximate measurement {614}. The calculated and measured values do not agree well, the form is, therefore, uncertain, accordingly omitted on the fig. 4. Measured: Calculated: 614: 010 = 13°54' 614 : 010 = 13°22'38' 614: {100} = 82-31' 614: 100 = 83°20'34' I noticed altogether 16 forms on the wolframite of Felsőbánya, viz. Three bases: a, b, c. Two prisms: m, d. Five domes of first order: y, k, t, i, Jc. One dome of second order: f. Five pyramides: co, o, o, e, *. KRENNER mentiones nine forms, viz. a, b, c, d, y, t, i, Jc, e, the remaining seven are, therefore, new for that habitat. KRENNER, otherwise, had found three forms: h {101}, v {552}, £ {132} which I could not find on my crystals. With these there are altogether nineteen forms known on the wolframite of Felsőbánya. The mesured and calculated values established by the present author are to be found on pag. 145—146 of the Hungarian text.