Elements of mineralogy, crystallography and blowpipe analysis from a practical standpoint .. . CHARACTERS OF MINERALS. 143 Fig. 322 shows a columnar beiyl. The columns may be parallelor not. Bladed.—A variety of columnar in which the columns are flat-tened like a knife blade, as in cyanite. Fibrous.—A variety of columnar in which the columns are slen-der threads or filaments-, as in Fig. 323, of the serpentine asbestosof Quebec, Canada. Lamellar Structure. The structure is said to be lamellar when the imperfectly formedcrystals appear as layers or plates, either straight or curved, as inthe mi
Elements of mineralogy, crystallography and blowpipe analysis from a practical standpoint .. . CHARACTERS OF MINERALS. 143 Fig. 322 shows a columnar beiyl. The columns may be parallelor not. Bladed.—A variety of columnar in which the columns are flat-tened like a knife blade, as in cyanite. Fibrous.—A variety of columnar in which the columns are slen-der threads or filaments-, as in Fig. 323, of the serpentine asbestosof Quebec, Canada. Lamellar Structure. The structure is said to be lamellar when the imperfectly formedcrystals appear as layers or plates, either straight or curved, as inthe mineral talc. Fig. 324. Foliated.—A variety of lamellar, in which the plates separateeasily. Micaceous.—A variety of lamellar in which the leaves can beobtained extremely thin, as in the micas. Granular Structures. The structure is said to be granular when the partially formedcrystals, appear as aggregations of angular grains, which may becoarse or fine, as in the marbles. Impalpable.—A variety of granular in which the grains are in-visible to the unassisted eye. Imitative Shapes.
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