What is "solidus"

late 14c., plural solidi, used of both English shilling and Roman gold coin, from Late Latin solidus, an imperial Roman coin (worth about 25 denarii), from nummus solidus, literally "solid coin," properly a coin of thick or solid metal, not of thin plate (see solid (adj.)).

n. 1 The line between the numerator and the denominator of a fraction. 2 A forward slash or virgule. 3 A late Roman gold coin (after 3rd Century CE); a bezant. 4 (context chemistry physics English) a line, in a phase diagram, below which a given substance is a stable solid and above which solid and liquid are in equilibrium

1. n. a gold coin of the Byzantine Empire; widely circulated in Europe in the Middle Ages [syn: bezant, bezzant, byzant]

2. a punctuation mark (/) used to separate related items of information [syn: slash, virgule, diagonal, stroke, separatrix]

3. [also: solidi (pl)]

Solidus ( Latin for "solid") may refer to:

• Solidus (coin), a Roman coin of nearly solid gold
• Solidus (punctuation), the formal name of the slash , from its former use marking the English shilling
• Solidus (chemistry), the line on a phase diagram below which a substance is completely solid
• Solidus (software), open-source software used for e-commerce
• Solidus Snake, a character in Metal Gear Solid 2: Sons of Liberty

The solidus ( Latin for "solid"; . solidi), nomisma (, nómisma, . "money"), or bezant was originally a relatively pure gold coin issued in the Late Roman Empire. Under Constantine, who introduced it on a wide scale, it had a weight of about 4.5 grams. It was largely replaced in Western Europe by Pepin the Short's currency reform, which introduced the silver-based pound/ shilling/ penny system, under which the shilling functioned as a unit of account equivalent to 12 pence, eventually developing into the French sou. In Eastern Europe, the nomisma was gradually debased by the Byzantine emperors until it was abolished by Alexius I in 1092, who replaced it with the hyperpyron, which also came to be known as a "bezant". The Byzantine solidus also inspired the originally slightly less pure Arabian dinar.

In late Antiquity and the Middle Ages, the solidus also functioned as a unit of weight equal to 1/72 of a pound.

In chemistry, materials science, and physics, the solidus is the locus of temperatures (a curve on a phase diagram) below which a given substance is completely solid (crystallized). The solidus is applied, among else, to metal alloys, ceramics, and natural rocks and minerals.

The solidus quantifies the temperature at which melting of a substance begins, but the substance is not necessarily melted completely, i.e., the solidus is not necessarily a melting point. For this distinction, the solidus may be contrasted to the liquidus. The solidus is always less than or equal to the liquidus, but they need not coincide. If a gap exists between the solidus and liquidus it is called the freezing range, and within that gap, the substance consists of a mixture of solid and liquid phases (like a slurry). Such is the case, for example, with the olivine ( forsterite- fayalite) system.

In eutectic mixtures the solidus and liquidus temperatures are identical, i.e., the mixture melts completely at one temperature, the eutectic point.

1. Redirect Solidus