Page:The New International Encyclopædia 1st ed. v. 13.djvu/469

MICA. 429 MICA SCHIST. salts. Ziimicahliti' is nS a complex composition, eoiituiniii^' iron in iulilition to the potassium, litliiuni, and aluminum silicates. In color it is of a pale violet or yellow to brown and dark gray. Uiulilv, or magnesium iron mica, is a magnesium, potassium, and iron silicate. It is usually (lark-colored, as green, brown, or black. PhtwjDpite is also a magnesium mica, generally nearly free from ircn. and usually containing some lluiu'inc. It is dark in color, being yellow- ish-brown to brownish-red. Lcpidonictune is an iron mica generally black in color. The micas occur in crysUilline rocks, muscovite being a normal constituent of granite, gneiss, and similar rocks. The deposits from which sheet mica is obtained are found in a coarse granite called pegmatite. The preparation of mica for the mar- ket is comparatively simple. TYk blocks, after being hoisted from the mine, are freed from ad- hering rock, and then split by means of wedges or heavy knives. After this the mica is cut np into sizes suitable for the market, usually in pound ])ackages. The mica waste is utilized as described previously under Muscovite. Consult the volumes of the Mineral Resources, United Slates Geological Survey (Washington, annual). MI'CAH (Heb. abbreviation of mikayah, in- terpreted a.s. 'Who is like Yahweh ?' ) . One of the minor prophets, a contemporary of Isaiah. His book is sixth in the ordinary arrangement of the minor prophecies, but third according to the Jewish canon, and this order is followed in the Septuagint. All that we know of his life is that he was a native of Moresheth, a small towTi dependent upon Gath ( Jlicah i. 1 ; .Jer. xxvi. 18) ; and that his activity falls in the reigns of Ahaz and Hezekiah, Init hardly in the days of Jotham, roughly speaking, therefore, between B.C. 734 and 700. The Book of Micah, in its present form, may be divided into three .sections, each beginning with "Hear ye." (1) Chapters i. and ii., ad- dressed to all the people, describe the coming of Yahweh in judgment on the transgressions of Israel and .Tudah, and the doom of Samaria; de- nounce luxury and covetousness as the sources of traiisgiession, and condenm the false prophets for leading the people astray; foretell the banish- ment of the ]ieople into captivity, and promise their return under the guidance of Yahweh. (2) Chapters iii.-v., addressed to the heads and princes of the people, condemn their oppressive rapacity, and declare that as they had been deaf to the cry of the poor in their wrongs, they, too, shall call on Yahweh. but will not be heard. The false prophets also who had deceived others shall themselves be made ashamed. This second threatening of judgment is followed by a second and fuller promise of Messianic times. (.S) In chapters vi. and vii., Yahweh. calling on the people to hear, and on the mountains to be wit- nesses of the controver.sy, appeals to all His past government over Israel as approving His right- eoTisness, The people, answering, complain that the burden of the sacrifices required is too great to l)e borne, and Yahweh. in reply, says that He asks of them only to do jnstlv. love mcrcv, and walk humbly with God. that' they had failed to comply with these demands is shown by the treasures of wickedness found in their houses, by the scant measures used, the false balances, the deceitful weights. For these crimes punishments will be inflicted; the wheat, the oil, and wine shall be cut off. The prophet mourns the justice of the sentence, and acknowledges the guilt of all classes of the people. Yet he waits for the salvation of Yahweh, triumphing in His pardon- ing mercy, which will certainly be manifested, and in His faithfulness, which will perform all tliat He had solemnly sworn to Abraham in the days of old. These three divisions, however, do not corre- spond either to the original order or character of the discourses embodied in the book. The first three chapters (with the exception of ii. 12-13) depict conditions prevalent prior to the destruction of Samaria, and may be attributed to the prophet Micah, though with editorial addi- tions and adjustment to the rest of the book. Chapters iv. and v., however, with their glimpse into Messianic times, embody the views and as- pirations of the struggling post-exilic religious community, weighted by the sense of guilt, regard- ing its own sufferings as a punishment for trans- gressions in the past, and looking forward to a redemption and restoration of national glory, which can only come from Y'ahweh Himself. There are reasons for supposing that chapters i.-v. once formed the entire Book of Micah, the first three being by the prophet himself, and forming the text as it were to the last two chapters, jus- tifying the sufferings in post-exilic days. Bj' w-ay of consolation, the prophecy of the Slessiah and Messianic times was compo.sed and added. In the same spirit, as a comment upon the real Micah, chapters vi. and vii. were written, which again present the same two sides — Yahweh's jus- tification in bringing such sufferings upon His people and the consolatory promises for the fu- ture. Chapters iv.-vii., according to this view, belong to the Persian period and probably to the later half. The text of the Book of ^licab. it should be added, is not well preserved, and this enhances the difficulties of a satisfactory inter- pretation. Consult, besides the general commen- taries on the Minor Prophets and the Old Testa- ment introductions, Caspari, Veber Micha den Morastliitcn tind seine prophet ische Schrift (Christiania, 18.51-.52) ; RoorAa.Commentarius in Vaticiniam .l/;>/ifC (Leyden. ISfiO) ; Cheyne, "The Book of JIicah,"in theCambridge Bible for Schools and Colleges (Cambridge, 1882) ; Ryssel. Unter- suchunf/eii iibcr die Textqestalt iind die Echtheit des Biiches Micha (Leipzig. 1887) : Taylor, The Mdssorrtic Tr.rt and the Ancient Vermons of the Book of MIcdh (London, 1891). MICA SCHIST. A metamorphic rock (q.v.) possessing a schistose or foliated structure and composed essentially of the minerals mica and quartz. The mica is generally the colorless va- riety known as muscovite (q.v.), though the dark variety, biotite, may be present also. When garnet or staurolite is present in addition to the quartz and mica, the rock is designated a garnetiferous or a staurolitic mica schist. Prob- ably the greater number of mica schists have been formed by the metamorphism of sedimentary rocks through the agency of orographic (moun- tain-building) forces. Other mica schists, and es- pecially the variety known as sericite schists, have been developed from acid igneous rocks (q.v.) by the action of the same forces. Of many mica schists, and especially those of pre- Cambrian age, it has been found impossible an yet to determine whether their origin is sedi- mentarj' or igneous.