Massive serpentine is used in considerable quantities as an ornamental stone, the green color varied with streaks and blotches of white, yellow and red, due to various impurities, making it very effective. It is, however, only suitable for interior work as the weather quickly spoils the polished surface. This is further discussed under serpentine rock, page 245. Serpentine is found at Newfane, Vt., Newburyport, Mass., Brewster, Antwerp, etc., N. Y., Hoboken, N. J., in Pennsylvania, Maryland, etc. Chlorite H₈(MgFe)₅Al₂(SiO₆)₃ Pl. 43 Occurs in monoclinic crystals of six-sided outline, or in scaly flakes or masses; hardness, 2; specific gravity 2.8; color green; luster pearly on cleavage faces; translucent on thin edges. Chlorite is a family name, covering a series of closely related minerals, so similar in appearance that they are best considered under this common name. In many respects they resemble mica, in the shape of the crystals and the remarkable basal cleavage. At first glance it is easy to confuse the two, but chlorite scales are not elastic, and when bent, stay bent, instead of snapping back like mica. In fact they look like more or less rotted micas. This is more than appearance, for chlorites form as a result of the alteration of micas in the presence of moisture. They are then secondary, and will be found where mica-rocks have been weathered, as in granites and schists. They may be expected anywhere that micas have been long exposed, as in New England, the Rocky Mountains, or the Sierra Nevada or Cascade Ranges. Special localities are Brewster, N. Y., Unionville and Texas, Penn., etc. The Zeolites The zeolites are a group of white minerals, with a pearly luster, light weight, and easy solubility in acids; which, because their contained water is lightly held, readily boil before the blowpipe. They are all secondary minerals, which result from the decomposition of feldspars, when exposed to weathering. They are almost universally found in seams and cavities of disintegrating lavas. From a group of a dozen or so, three are common enough to be considered here. They may be found by watching such places, as where trap rock is being quarried for road material, or being blasted for any reason. Analcite Na₃Al₂Si₄O₁₃ + 2H₂O Pl. 44 Occurs as trapezohedrons in seams and cavities in lavas; hardness, 5.5; specific gravity, 2.2; colorless, white or pink; luster vitreous; transparent on thin edges. Analcite usually occurs in the 24-sided form, known as a trapezohedron, as illustrated in figure A, Pl. 44; but it may also occur in cubes with the three faces of the trapezohedron on each corner. Small crystals are often colorless, but the larger ones are either white or pink, and are opaque. While the form is the same as that of garnets, the color, lesser hardness, and the occurrence in lavas will serve to distinguish this mineral. If placed in hydrochloric acid analcite dissolves to a gelatinous mass.