From BiblePortal Wikipedia

Watson's Biblical & Theological Dictionary [1]

ראמות ,  Job 28:18;  Ezekiel 27:16; a hard, cretaceous, marine production resembling in figure the stem of a plant, divided into branches. It is of different colours—black, white, and red. The latter is the sort emphatically called coral, as being the most valuable, and usually made into ornaments. This, though no gem, is ranked by the author of the book of  Job 28:18 , with the onyx and sapphire. Dr. Good observes, "It is by no means certain what the words here rendered ‘corals and pearls,' and those immediately, afterward rendered ‘rubies and topaz,' really signified. Reiske has given up the inquiry as either hopeless or useless; and Schultens has generally introduced the Hebrew words themselves, and left the reader of the translation to determine as he may. Our common version is, in the main, concurrent with most of the oriental renderings: and I see no reason to deviate from it."

Fausset's Bible Dictionary [2]

More precious in ancient times than now, when it is more easily procured ( Job 28:18;  Ezekiel 27:16). The red coral is the stony skeleton of a red zoophyte. In the Mediterranean, on the African coast off Tunis, attached to the rock at a considerable depth, and broken off from them by long hooked poles, and thus drawn out (Hebrew for "price,"  Job 28:18, is Meshek , "the drawing out".) From Carthage (where Tunis now stands) the rough coral was imported to the mother city Tyre, and there manufactured into ornaments to be purchased by merchants for the women of Syria. Its tree-like growth is implied by its name Ramoth , from Raam "to be high"; others from the Sanskrit Ramye , "pleasant."

King James Dictionary [3]

CORAL, n. L. Gr.

1. In zoology, a genus belonging to the order of vermes zoophyta. The trunk is radicated, jointed and calcarious. The species are distinguished by the form of their branches, and are found in the ocean adhering to stones, bones, shells, &c. Coral was formerly supposed to be a vegetable substance, but is now known to be composed of a congeries of animals. Coral is red, white and black. It is properly the shells of marine animals of the polype kind, consisting of calcarious earth combined with gelatine and other animal matter. In the South Sea, the isles are mostly coral rocks covered with earth. Corals seem to consist of carbonate of lime and animal matter, in equal proportions. 2. A piece of coral worn by children about their necks.

CORAL, a. Made of coral resembling coral.

American Tract Society Bible Dictionary [4]

A hard calcareous, marine production, produced by the labors of millions of insects, and often resembling in figure the stem of a plant, divided into branches. It is of various colors, black, white, and red. The latter is the most valuable. It is ranked by  Job 28:18 , and  Ezekiel 27:16 , among precious stones. It abounds in the Red sea; and the islands of the South seas are often coral reefs, covered over with earth. The word "rubies" in  Proverbs 3:15;  8:11;  20:15;  31:10 , is thought by many to mean ornaments of coral.

Smith's Bible Dictionary [5]

Coral.  Ezekiel 27:16. A production of the sea, formed by minute animals called Zoophytes. It is their shell or house. It takes various forms, as of trees, shrubs, hemispheres. The principal colors are red and white. It was used for beads and ornaments.

With regard to the estimation in which coral was held by the Jews and other Orientals, it must be remembered that coral varies in price with us. Pliny says that the Indians valued coral as the Romans valued pearls.  Job 28:18.

Easton's Bible Dictionary [6]

 Job 28:18 Ezekiel 27:16

The coral is a cretaceous marine product, the deposit by minute polypous animals of calcareous matter in cells in which the animal lives. It is of numberless shapes as it grows, but usually is branched like a tree. Great coral reefs and coral islands abound in the Red Sea, whence probably the Hebrews derived their knowledge of it. It is found of different colours, white, black, and red. The red, being esteemed the most precious, was used, as noticed above, for ornamental purposes.

Webster's Dictionary [7]

(1): (n.) A piece of coral, usually fitted with small bells and other appurtenances, used by children as a plaything.

(2): (n.) The ovaries of a cooked lobster; - so called from their color.

(3): (n.) The hard parts or skeleton of various Anthozoa, and of a few Hydrozoa. Similar structures are also formed by some Bryozoa.

Morrish Bible Dictionary [8]

The Hebrew word is ramoth, and occurs only in  Job 28:18 and   Ezekiel 27:16 : it signifies high priced or costly things. The Rabbis think it refers to red coral.

Holman Bible Dictionary [9]

Corallium rubrum  Job 28:12-18 Ezekiel 27:16

Hastings' Dictionary of the Bible [10]

CORAL . See Jewels and Precious Stones.

International Standard Bible Encyclopedia [11]

kor´al ( ראמות , rā'mōth , פנינים , penı̄nı̄m ): The red coral or precious coral, Corallium rubrum , is confined to the Mediterranean and Adriatic seas. It is the calcareous axis of a branching colony of polyps. It does not form reefs, but occurs in small masses from 40 to 100 fathoms below the surface. It differs totally in structure from the white corals which form coral reefs, belonging to the order of Octactinia or Eight-rayed Polyps, while the reef-building corals belong to the Hexactinia or Six-rayed Polyps.

Rā'mōth , apparently from r. rā'am , "to be high" (compare rūm , "to be high"), occurs in three passages. In  Proverbs 24:7 , Evv have "too high": "Wisdom is too high for a fool." In  Job 28:12-19 , where various precious things are compared with wisdom, English Versions of the Bible has "coral"(King James Version, margin "Ramoth"). It is mentioned here along with ṣeghōr , "gold" (the Revised Version, margin "treasure"); kethem , "gold of Ophir"; shōham , "onyx" (the Revised Version, margin "beryl"); ṣappı̄r , "sapphire"; zāhābh , "gold"; zekhūkhı̄th , "crystal" (the Revised Version (British and American) "glass"); pāz , "gold"; gābhı̄sh , "pearls" (the Revised Version (British and American) "crystal"); penı̄nı̄m , "rubies" (the Revised Version, margin "red coral" or "pearls"); piṭedhāh , "topaz." While the real meaning of some of these terms is doubtful (see Stones , Precious ), they all, including rā'mōth , appear to be precious stones or metals. In  Ezekiel 27:16 , ה , rā'mōth occurs with nōphekh , "emeralds" (the Revised Version, margin "carbuncles"); 'argāmān , "purple"; riḳmāh , "broidered work"; būc , "fine linen"; kadhkōdh , "agate"(King James Version, margin "chrysoprase," the Revised Version (British and American) "rubies"). Here the context does not require a precious stone or metal, and Vulgate (Jerome's Latin Bible , 390-405 ad) has sericum , i.e. "Chinese material" or "silk." Notwithstanding, therefore, the traditional rendering, "coral," the real meaning of rā'mōth must be admitted to be doubtful.

Penı̄nı̄m (from the root pānan , "to divide up," "to separate"; compare Arabic fanan , "a branch of a tree") occurs in  Job 28:18;  Proverbs 3:15;  Proverbs 8:11;  Proverbs 20:15;  Proverbs 31:10;  Lamentations 4:7 . In all these passages English Versions of the Bible has "rubies" ( Job 28:18 , the Revised Version, margin "red coral" or "pearls";  Lamentations 4:7 , the Revised Version, margin "corals"). Everywhere a precious substance is indicated, but nowhere does the context give any light as to the nature of the substance, except in  Lamentations 4:7 , where we have the statement that the nobles of Jerusalem "were more ruddy in body" than penı̄nı̄m ̌ . This and the etymology favor a branching red substance such as precious coral. The occurrence of penı̄nı̄m and rā'mōth together in  Job 28:18 is, if we give the precedence to penı̄nı̄m , a further argument against rā'mōth meaning "coral."

Kitto's Popular Cyclopedia of Biblial Literature [12]

Coral , a hard, cretaceous marine production arising from the deposit of calcareous matter by a minute polypus animal, in order to form the cell or polypidom into whose hollows the tenant can wholly or partially retire. The corals thus produced are of various shapes, most usually branched like a tree. The masses are often enormous in the tropical seas, where they top the reefs and cap the submarine mountains, frequently rising to or near the surface so as to form what are called coral islands and coral reefs. These abound in the Red Sea; from which, most probably, was derived the coral with which the Hebrews were acquainted; but coral is also found in the Mediterranean. It is of different colors, white, black, red. The red kind was anciently, as at present, the most valued, and was worked into various ornaments.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [13]

Bibliography Information McClintock, John. Strong, James. Entry for 'Coral'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. Harper & Brothers. New York. 1870.