Well, that’s one common material of choice for drinking cups back then. Alternatively, you have stoneware, which was less susceptible to ritual uncleanliness in Jewish thought when compared to ordinary pottery - and which were more expensive and difficult to manufacture.
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A stack of pottery goblets from Qumran
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Two stone cups, also from Qumran
The Greek word used in the Last Supper narrative is ποτήριον
potērion (originally a diminutive of ποτήρ
potēr, “cup” from πίνω
pinō, “I drink”). The word appears in the following instances in the New Testament:
1.) The ποτήριον of wine that Jesus passed around at the Last Supper (Matthew 26:27; Mark 14:23; Luke 22:17, 20; 1 Corinthians 11:25), by extension the “ποτηρίων of the Lord” (1 Corinthians 10:16, 21, 26-27)
2.) The “ποτήριον of demons” which St. Paul contrasts with that of the Lord (1 Corinthians 10:20/1)
3.) The ποτήριον of suffering that Jesus must drink (Matthew 20:22-23, 26:39; Mark 10:38-39, 14:36; Luke 22:42; John 18:11)
4.) Anyone who gives a ποτήριον of (cold) water to a disciple of Jesus will not be without reward (Matthew 10:42; Mark 9:40/1)
5.) Jesus accuses the Pharisees of cleaning the “outside of the ποτήριον and of the dish” (Matthew: τοῦ ποτηρίου καὶ τῆς παροψίδος, Luke: τοῦ ποτηρίου καὶ τοῦ πίνακος) while neglecting the inside (Matthew 23:25-26; Luke 11:39)
6.) The ποτήριον of God’s wrath which is to be given to the wicked and to Babylon (Revelation 14:10; 16:19)
7.) The golden ποτήριον of the Whore of Babylon (Revelation 17:4)
8.) The voice from heaven tells God’s people to “mix a double portion for [Babylon] in the ποτήριον she mixed” (Revelation 18:6)
In the Latin Vulgate:
1.)-
3.) ποτήριον is usually rendered as
calix.
4.) Matthew 10:42; Mark 9:40/1: ποτήριον ψυχροῦ/ὕδατος is rendered as
calicem aquae (frigidae)
5.) Matthew 23:25-26; Luke 11:39: τοῦ ποτηρίου καὶ τῆς παροψίδος/τοῦ πίνακος is rendered as
calicis et parapsidis/catini
6.) Revelation 14:10: τῷ ποτηρίῳ τῆς ὀργῆς αὐτοῦ is rendered as
calice irae ipsius; Revelation 16:19: τὸ ποτήριον τοῦ οἴνου τοῦ θυμοῦ τῆς ὀργῆς αὐτοῦ is rendered as
calicem vini indignationis irae eius
7.) Revelation 17:4: ποτήριον χρυσοῦν is rendered as
poculum aureum
8.) Revelation 18:6: ποτηρίῳ is rendered as
poculo
We can see here that the Vulgate mostly renders the word ποτηρίου as
calix (even that of the demons in 1 Corinthians 10); it only chooses another word,
poculum, in the context of the Babylon. (So no, anti-Catholics can’t accuse the Church as being the Whore because of the “
golden cup” she holds in her hand and whatnot; I mean, that was a
poculum, not a
calix!

)