Nines are an informal logarithmic notation for proportions very near to one or, equivalently, percentages very near 100%. Put simply, "nines" are the number of consecutive nines in a percentage such as 99% (two nines) [1] or a decimal fraction such as 0.999 (three nines). Their common uses include grading the purity of materials.
The nines are a count of the leftmost digits 9 that appear in a proportion. For example, 90% would be described as "one nine"; 99% as "two nines"; 99.9% as "three nines"; and so forth.
However, there are different conventions for representing inexact multiples of 9. For example, a percentage of 99.5% could be expressed as "two nines five" (2N5, or N2.5) [2] or as 2.3 nines,[ citation needed ] following from the logarithm definition.
A percentage of 100% would, in theory, have an infinite number of nines – though, in the context of purity of materials, 100% is virtually unachievable. [3]
| Percent | Permille | Nines | ||
|---|---|---|---|---|
| 90% | 900 | 1 nine | 1N | N1.0 |
| 99% | 990 | 2 nines | 2N | N2.0 |
| 99.9% | 999 | 3 nines | 3N | N3.0 |
| 99.95% | 999.5 | 3 nines 5 | 3N5 | N3.5 |
| 99.97% | 999.7 | 3.5 nines[ citation needed ] | ? | ? |
| 99.99% | 999.9 | 4 nines | 4N | N4.0 |
| 99.995% | 999.95 | 4 nines 5 | 4N5 | N4.5 |
| 99.999% | 999.99 | 5 nines | 5N | N5.0 |
| 99.9999% | 999.999 | 6 nines | 6N | N6.0 |
The number of nines of a proportion x is:[ citation needed ]
The exact purity of very fine precious metals such as platinum, gold and silver can be of great interest. Based on the system of millesimal fineness, a metal is said to be one nine or one nine fine if it is 900 fine, or 90% pure. A metal that is 990 fine is then described as two nines fine and one that is 999 fine is described as three nines fine. Thus, nines are a logarithmic scale of purity for very fine precious metals. Similarly, percentages ending in a 5 have conventional names, traditionally the number of nines, then "five", so 999.5 fine (99.95% pure) is "three nines five", abbreviated 3N5.
Canada's Big Maple Leaf, a coin made of gold at 5N (99.999%) purity, stands as the purest gold coin ever minted, anywhere. [4] The purest gold ever achieved was reportedly produced at the Perth Mint in 1957, at "almost six nines" (99.9999%) purity, as measured by the Worshipful Company of Goldsmiths of London. [5]
The nines scale is also used in other contexts, such as describing the purity of gases. The purity of a gas is an indication of the ratio of it to other gases in its mixture, as measured by volume. Thus, a high purity refers to a low amount of other gases, or impurities. Gases of higher purity are in many contexts considered to be of better quality and are usually more expensive.
The purity of a gas is generally expressed as a grade prefixed with the letter N (rather than postfixed), indicating the "number of nines" in the percentage or decimal fraction. For example, a N2.0 gas is 99% (two nines) pure and 1% impurities by volume; a N6.0 gas is 99.9999% (six nines) pure, with 1 part per million (1 ppm or 1 vpm, volume per million) impurities. [6]
Intermediate values indicate the digit following the last nine. For example, N4.6 estimates a purity level of 99.996% (four nines followed by a six). [6] An alternative representation uses the common logarithm: for example, a gas which is 99.97% pure would be described as N3.5, since log10(0.03%) = −3.523.[ citation needed ]
Nines are used in a similar manner to describe computer system availability. In this context, a "one nine" (90%) uptime indicates a system that is available 90% of the time or, as is more commonly described, unavailable 10% of the time – about 72 hours per month. [7] A "five nines" (99.999%) uptime describes a system that is unavailable for at most 26 seconds per month. [7]
Five nines, commonly taken to mean "99.999%", may refer to:
Precious metals are rare, naturally occurring metallic chemical elements of high economic value. Precious metals, particularly the noble metals, are more corrosion resistant and less chemically reactive than most elements. They are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment and industrial raw materials. Gold, silver, platinum, and palladium each have an ISO 4217 currency code.
The Royal Canadian Mint is the mint of Canada and a Crown corporation, operating under the Royal Canadian Mint Act. The shares of the Mint are held in trust for the Crown in right of Canada.
Bullion is non-ferrous metal that has been refined to a high standard of elemental purity. The term is ordinarily applied to bulk metal used in the production of coins and especially to precious metals such as gold and silver. It comes from the Anglo-Norman term for a melting-house where metal was refined, and earlier from French bouillon, "boiling". Although precious metal bullion is no longer used to make coins for general circulation, it continues to be held as an investment with a reputation for stability in periods of economic uncertainty. To assess the purity of gold bullion, the centuries-old technique of fire assay is still employed, together with modern spectroscopic instrumentation, to accurately determine its quality.
The fineness of a precious metal object represents the weight of fine metal therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass.
The Canadian Gold Maple Leaf (GML) is a gold bullion coin that is issued annually by the Government of Canada. It is produced by the Royal Canadian Mint.
The Perth Mint is Australia's official bullion mint and wholly owned by the Government of Western Australia. Established on 20 June 1899, two years before Australia's Federation in 1901, the Perth Mint was the last of three Australian colonial branches of the United Kingdom's Royal Mint intended to refine gold from the gold rushes and to mint gold sovereigns and half-sovereigns for the British Empire. Along with the Royal Australian Mint, which produces coins of the Australian dollar for circulation, the Perth Mint is the older of Australia's two mints issuing coins that are legal tender.
This glossary of numismatics is a list of definitions of terms and concepts relevant to numismatics and coin collecting, as well as sub-fields and related disciplines, with concise explanations for the beginner or professional.
High availability (HA) is a characteristic of a system that aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period.
The Miller process is an industrial-scale chemical procedure used to refine gold to a high degree of purity (99.5%). It was patented by Francis Bowyer Miller in 1867. This chemical process involves blowing chlorine gas through molten, but (slightly) impure, gold. Nearly all metal contaminants react to form chlorides but gold does not at these high temperatures. The other metals volatilize or form a low density slag on top of the molten gold.
The Canadian Silver Maple Leaf is a silver bullion coin that is issued annually by the Government of Canada since 1988. It is produced by the Royal Canadian Mint.
In metallurgy, refining consists of purifying an impure metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material, whereas in refining, the final material is usually identical chemically to the original one, only it is purer. The processes used are of many types, including pyrometallurgical and hydrometallurgical techniques.
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure.
Traditionally, Olympic coins are numismatic coins. However, several host countries minted so many coins – particularly silver ones – that their value has become just slightly above the value of their metal content. Coins for the 1976 Montreal, 1984 Los Angeles, and 1988 Seoul are generally considered to fall into that category.
Silver standards refer to the standards of millesimal fineness for the silver alloy used in the manufacture or crafting of silver objects. This list is organized from highest to lowest millesimal fineness, or purity of the silver.
A metallurgical assay is a compositional analysis of an ore, metal, or alloy, usually performed in order to test for purity or quality.
A gold coin is a coin that is made mostly or entirely of gold. Most gold coins minted since 1800 are 90–92% gold (22‑karat), while most of today's gold bullion coins are pure gold, such as the Britannia, Canadian Maple Leaf, and American Buffalo. Alloyed gold coins, like the American Gold Eagle and South African Krugerrand, are typically 91.7% gold by weight, with the remainder being silver and copper.
The Vienna Philharmonic, often shortened to Philharmonic, is a bullion coin of gold, silver, or platinum produced by the Austrian Mint. The coin is named for the Vienna Philharmonic orchestra, which inspired the design of both sides. It was introduced in 1989 as a one-troy ounce (ozt), gold coin with a face value of 2,000 Austrian schillings. It is generally one of the world's best selling bullion coins. In 2002, with the adoption of the euro currency, the nominal value of the one-ounce coin was changed to 100 euros. In 2008, the Mint introduced a one-ounce silver version of the coin with a nominal value of 1.50 euros. The silver coin is also one of the top selling bullion coins, ranked third in 2013. In 2016, the mint introduced a one ounce platinum coin with a face value of 100 euros.
PAMP SA is an independently operated precious metals refining and fabricating company and member of the MKS Group. It was established in 1977 in Ticino, Switzerland.
Electrolytic iron is a form of high purity iron, obtained by electrolysis. It has a high purity greater than 99.95% with trace elements accounting for only a millionth of a decimal.
For example, the difference between a purity of aluminum of "four nines" and "six nines" is understandable to a scientist, but not necessarily to a politician. (These are 99.99 percent pure and 99.9999 percent pure).
For example, good commercial-grade gases for plasma spraying are stated to be at least 99.995% ("four-nines-five" purity).
Therefore, in reality, it's virtually impossible to have a 100% chemically pure substance that maintains its purity for an extended period of time.
At "five nines pure" (99.999%) the gold contained less than 10 parts per million of other elements like silver, aluminum and zirconium, one decimal place purer and hundreds of thousands of dollars more valuable than any gold coinage minted in Vienna or elsewhere, ever.
We achieved "arguably the purest of all gold" in 1957. Refinery Officer Leo Hickey and Senior Craftsman Alexander Osborne produced a proof 'plate' of almost six nines - 999.999 parts of gold per thousand - as measured by the Worshipful Company of Goldsmiths in London.
