Tablets of Stone
According to the Hebrew Bible, the Tables of the Law as they are widely known in English, or Tablets of Stone, Stone Tablets, or Tablets of Testimony (in Hebrew: לוחות הברית Luchot HaBrit - "the tablets [of] the covenant") in the Exodus 34:1, were the two pieces of stone inscribed with the Ten Commandments when Moses ascended Mount Sinai as written in the Book of Exodus. Exodus 31:18 refers to the tablets as the "Tablets of (the) Testimony".
According to the biblical narrative there were two sets of tablets. The first, inscribed by the finger of God, (Exodus 31:18) were smashed by Moses when he was enraged by the sight of the Children of Israel worshipping a golden calf (Exodus 32:19) and the second were later cut and rewritten by Moses in accordance with his declaration in Exodus 34:1. (Exodus 34:28)[not in citation given (See discussion.)]
According to traditional teachings of Judaism in the Talmud, they were made of blue sapphire stone as a symbolic reminder of the sky, the heavens, and ultimately of God's throne. Many Torah scholars, however, have opined that the Biblical "sapir" was, in fact, the lapis lazuli (see Exodus 24:10, lapis lazuli is a possible alternate rendering of "sapphire" the stone pavement under God's feet when the intention to craft the tablets of the covenant is disclosed Exodus 24:12). 
Appearance of the tabletsEdit
In recent centuries the tablets have been popularly described and depicted as round-topped rectangles but this has little basis in religious tradition. According to rabbinic tradition, they were rectangles, with sharp corners, and indeed they are so depicted in the 3rd century paintings at the Dura-Europos Synagogue and in Christian art throughout the 1st millennium, drawing on Jewish traditions of iconography.
The rounded tablets appear in the Middle Ages, following in size and shape contemporary hinged writing tablets for taking notes (with a stylus on a layer of wax on the insides). For Michelangelo and Andrea Mantegna they still have sharp corners (see gallery), and are about the size found in rabbinic tradition. Later artists such as Rembrandt tended to combine the rounded shape with the larger size. While, as mentioned above, rabbinic tradition teaches that the tablets were squared, according to some authorities, the Rabbis themselves approved of rounded depictions of the tablets in replicas so that the replicas would not exactly match the historical tablets.
According to the Talmud, the length and width of each of the Tablets was six Tefachim, and each was three Tefachim thick - roughly 50 and 25 centimetres (20 and 10 in) respectively, though they tend to be shown larger in art. Also according to tradition, the words were not engraved on the surface, but rather were bored fully through the stone.
In Jewish religious tradition, the arrangement of the commandments on the two tablets is interpreted in different ways. Rabbi Hanina ben Gamaliel said that each tablet contained five commandments, "but the Sages say ten on one tablet and ten on the other". Because the commandments establish a covenant, it is likely that they were duplicated on both tablets. This can be compared to diplomatic treaties of Ancient Egypt, in which a copy was made for each party. But the tablets may have contained not only the Ten Commandments but also additional precepts and words as can be inferred from the verses Exodus 31:18, Exodus 34:1, Exodus 34:27-28. 
Replicas of the tablets, known as tabots or sellats, are a vital part of the practice of Ethiopian Orthodox Church, which claims that the original Ark of the Covenant is kept in the Church of Our Lady Mary of Zion in Axum.
In the Qur'anEdit
- "And We ordained laws for him in the tablets in all matters, both commanding and explaining all things, (and said): 'Take and hold these with firmness, and enjoin thy people to hold fast by the best in the precepts: soon shall I show you the homes of the wicked,- (How they lie desolate).'" (Quran 7:145)
These tablets are not broken in the Quran, but picked up later:
- "When Moses came back to his people, angry and grieved, he said: 'Evil it is that ye have done in my place in my absence: did ye make haste to bring on the judgment of your Lord?' He put down the tablets, seized his brother by (the hair of) his head, and dragged him to him..." (Quran 7:150). "When the anger of Moses was appeased, he took up the tablets: in the writing thereon was guidance and Mercy for such as fear their Lord." (Quran 7:154).
- Exodus 31:18
- See: Staples, W. E., "Lapis Lazuli", in The Interpreter's Dictionary of the Bible, vol.3, p. 72
- Bava Batra 14a.
- Except for a variant tradition where a scroll is shown, only known from Christian examples. 
- See HaQoton, Reb Chaim "Squared vs. Rounded Tablets" (also available on academia.edu)
- Bava Batra 14a.
- Rabbi Ishmael. Horowitz-Rabin (ed.), ed. Mekhilta. pp. 233, Tractate de-ba-Hodesh, 5.CS1 maint: Extra text: editors list (link)
- Margaliot, Dr. Meshulam (July 2004). "What was Written on the Two Tablets?". Bar-Ilan University. Retrieved 2006-09-20.
- "Adam Clarke Commentary".
- Paul Raffaele, "Keepers of the Lost Ark?" Smithsonian Magazine, December 2007 (accessed 9 April 2011)