BARITE resembles calcite because it can be scratched with a knife and has three smooth cleavage planes. It differs in having one cleavage perpendicular to the other two, which intersect at angles of 78°. The mineral is more than four times the weight of an equal volume of water, and it feels heavy. It is found in the lead veins at West Farms, Hatfield and Leverett. In large quantities it has commercial value as a source of the element barium, for it is the sulphate of barium (BaSO₄). GALENA is the chief metallic mineral in the veins at Leverett, Hatfield and Loudville. It is very heavy and has a metallic gray color; it breaks into perfect cubes. A knife scratches it easily and crumbles it to a black powder. The mineral is a lead sulphide (PbS). SPHALERITE is a lustrous, resinous brown mineral in these same veins. It cleaves into multi-faced fragments and is softer than a knife. Chemically it is the sulphide of zinc (ZnS). PYRITE is the deceptive golden-colored, metal-like mineral which has earned the name of “fool’s gold.” It will scratch glass, and it crushes to a black powder. The materials in it are iron and sulphur (FeS₂). CHALCOPYRITE resembles pyrite but will not scratch glass and has a greenish yellow color. It is a compound of copper, iron and sulphur (CuFeS₂). The veins in the Connecticut Valley region contain many other minerals, among which must be mentioned datolite, natrolite, apophyllite, thomsonite, fluorite and babbingtonite in the lavas; and siderite, rhodochrosite, rhodonite, wulfenite and pyromorphite in the older veins of the highlands. _Minerals of Pegmatites and Igneous Rocks_ The minerals found in pegmatites are legion. More than thirty can be collected on any trip to Collins Hill near Portland, Connecticut, or to the Ruggles Mine near Grafton Center, New Hampshire. Only the minerals appearing most commonly in pegmatites are described, but a list of others is appended as an aid in consulting a textbook. Igneous rocks contain practically the same suite of minerals as pegmatites, but in smaller grains. MICROCLINE is a white to flesh-colored feldspar with two almost perpendicular cleavages. It will scratch glass or a knife. One cleavage face shows a grid of translucent and transparent lines intersecting at 90°. ALBITE is the second most abundant feldspar. It is white and may generally be recognized by its two cleavage surfaces at 86°. Its growth may be likened to piling a series of plates with their surfaces parallel to one of the cleavages; during growth the plates are laid alternately face up and face down, so that the 86° cleavage edges zigzag in and out, forming a surface which, on the average, is perpendicular to the growth cleavage surface. The separate plates can usually be detected as fine bands or striations. The mineral scratches either glass or a knife.