MINERALS 93 



and cavities in the rock. Calcite was the first and the 

 last mineral to be deposited in these cavities. The 

 earlier deposit is in granular form, the later in distinct 

 crystals, some of them half an inch in length, showing 

 combinations of the forms M(4O4i), f (0221), and L(o887); 

 the first two have bright reflecting planes but the negative 

 rhombohedron (L) forms a somewhat rounded, dull ter- 

 mination. Stilbite forms drusy coatings of characteristic 

 platy crystals, showing the ordinary forms. The laumon- 

 tite, which is the most abundant mineral, is in fibrous 

 masses or single acicular crystals of pale pink color, 

 showing square cross-section and an inclined terminal 

 plane where they project into an open cavity. The crystals 

 are not measurable, but the mineral was certainly deter- 

 mined by its crumbling character, its form and its chemical 

 behavior. 



In describing the syenite-porphyry of Stepovak Bay 

 (page 82), mention was made of small cavities filled 

 with epidote. The crystals are minute but they are 

 sharply formed and prove to be measurable. The follow- 

 ing forms are found: c(ooi), b(oio), a(ioo), e(ioi), 

 1(102), r(Ioi), 0(011), n(in), and y(2ii). The crystals 

 are prismatic parallel to the axis b, and are terminated by 

 a broad plane of b with extremely narrow faces of o, n, 

 and y about it. 



In another phase of this porphyry the amygdules are 

 filled with finely fibrous laumontite and a core of calcite, 

 and in one of the cavities the calcite forms a distinct 

 and measurable crystal, a combination of M(4O4i) and 

 (0221) with rather rounded faces of the scalenohedron 



In the following catalogue of the minerals found by the 

 Harriman Expedition, rock-forming minerals are excluded 

 except in one or two cases where the mineral was unusual 

 or of eminent size or striking character. 



