Metals Glossary

We cre­ated this sec­tion to help you un­der­stand some of the terms com­monly used to ex­press pre­cious metals pur­ity, volume, and weight meas­ure­ments. We will be ex­pand­ing this sec­tion, so if there are spe­cif­ic terms you wish to learn more about, please let us know, and we will make sure to add the rel­ev­ant in­form­a­tion with our fu­ture up­dates.

Bullion Coin

Des­pite the fact that golden money was sub­sti­tuted by pa­per bank notes a long time ago, in­vest­ing money in gold re­mains the most ef­fi­cient way to hold cap­it­al and to in­sure it against de­pre­ci­ation. People tend to in­sure their sav­ings, es­pe­cially dur­ing re­ces­sions or wars, by con­vert­ing their money in­to gold, which nev­er loses value.

One of the ways to save is buy­ing bul­lion coins that are is­sued by banks spe­cific­ally for sav­ing. These coins are usu­ally labeled by hall­marks in­dic­at­ing mass (in oz) and some­times in­dic­at­ing nom­in­al value. The labeled nom­in­al value is al­ways lower than the true value be­cause a bul­lion coin is a piece of jew­elry.

The first bul­lion coin was is­sued in the South Afric­an Re­pub­lic (SAR) in 1967. Today, bul­lion coins are is­sued in al­most all coun­tries of the world, and the most fam­ous gold coins come from Aus­tralia, United King­dome, SAR, US, France, and Rus­sia. Gen­er­ally, col­lec­tion and an­niversary coins made of gold, pal­la­di­um, or plat­in­um may be re­garded as bul­lion coins. The metals men­tioned are usu­ally used for pro­du­cing bul­lion coins.

Ingot

In­got is a bar of sil­ver or gold used for sav­ing cap­it­al - in much the same way as with bul­lion coins. In­gots vary by weight, shape, and means of pro­duc­tion. In­gots are usu­ally cast: met­al is smelted, poured in­to a form, and then so­lid­i­fied as­sum­ing the shape of the form. There are also chased in­gots cut from flat platens of met­al with each bar labeled with a stamp. Re­cently, an­oth­er way of stor­ing gold has been de­veloped– a Chip Gold in­got. This is a small bar of gold (un­der 20 g or 0.7 oz) pressed in­to a spe­cial pack­aging that looks like a cred­it card.

Golden in­gots came in­to use in 6th cen­tury B.C. They were used in ma­jor cit­ies as cur­rency in the trad­ing pro­cess. Be­cause gold and sil­ver needed to be weighed every time there was a trans­ac­tion, the free ex­change pro­cess was in­con­veni­ent. Labeled in­gots ap­peared in 6th cen­tury BC in Ly­dia. They were made of sil­ver and gold al­loyed in cer­tain pro­por­tions. The al­loy was called elec­trum. The idea of cast­ing in­gots and us­ing them for trad­ing was such an ap­pre­ci­ated ad­vance that in merely 45-50 years, all pay­ments were made with in­gots.

Karat

There are two spellings of the word car­at. Car­at spelled with a "C" and ab­bre­vi­ated as "ct" is the con­ven­tion­al unit used by jew­el­ers world­wide to meas­ure volume, mass, and pur­ity of pearls and gem­stones. More in­form­a­tion about the car­at is avail­able in Gem­stones Gloss­ary. Kar­at spelled with a "K" and ab­bre­vi­ated as "K" is used for de­fin­ing the pur­ity of pre­cious metals.

To in­dic­ate how much pre­cious met­al an al­loy con­tains, the Brit­ish sys­tem of hall­marks is used: an amount of al­loy con­sists of 24 nom­in­al por­tions; one por­tion stands for one car­at, which is marked by let­ter K. So, if all the por­tions an al­loy con­tains are gold, it in­dic­ates a pure, sol­id gold con­tain­ing no oth­er ad­mix­tures and is hall­marked with 24K. Eight­een kar­at gold (18K) means that met­al con­tains 18 parts of gold and 6 parts of ad­mix­tures. In much the same way, one can as­sume that 14K gold con­tains 10 parts of ad­mix­tures, and 10K gold con­tains 14 parts of ad­mix­tures, etc.

In the US and Europe, the pur­ity of gold is meas­ured in kar­ats, while in the coun­tries of the former USSR it is meas­ured by the milles­im­al stand­ard. The milles­im­al stand­ard is the three di­git num­ber that is some­times provided after the karatage. The milles­im­al stand­ard, an­oth­er way to de­note the pur­ity of a met­al, refers to the parts per thou­sand that are pure gold. Gold bars usu­ally con­sist of pure gold, which is 24-kar­at gold (999.9). The least pure gold is 9-kar­at gold (375) or 10-kar­at gold (417). The most fre­quently used golds in the jew­elry in­dustry are the 14-kar­at (583) and the 18-kar­at gold (750).

Troy Ounce

The Troy ounce is a gen­er­ally ap­proved unit for meas­ur­ing the weight of in­gots and bul­lion coins, as well as of some oth­er un­re­lated pre­cious sub­stances. One troy unit equals 31.1 g or 1.1 oz. The Troy weight of gold is in­dic­ated as XAU (Au is the chem­ic­al ab­bre­vi­ation of gold). In the same man­ner, the troy weight of sil­ver is XAG (Ag for Ar­gentum), XPT for plat­in­um, XPD for pal­la­di­um etc.

The Ro­man ounce differed a bit from the Troy weight unit; it equals 27.28 g or 0.96 oz. Troy weight was named after the town of Troyes, which is situ­ated in the north­ern part of France. Nowadays, it is a small town, but in Me­di­ev­al Europe it was one of the most sig­ni­fic­ant trade cen­ters with spec­tac­u­lar fairs. Troyes was also fam­ous for the most pre­cise weigh­ing ma­chines, which is why the weight unit used for the most pre­cise meas­ure­ments is named after Troyes.