Does all jewelry have ahallmark? How to test perals/ How to determine a rubt from a garnet? and diamonds from rhimestones?
No, many older pieces (and/or pieces from many other countries) do not have a hallmark.
Some retailers will get the pieces hallmarked before selling, but many will not, as it is considered better to keep them in prime condition.
In the UK, if you do not hallmark the pieces (with the minimum UK hallmark), you cannot sell many of them (with some exceptions, below) as being made of gold, or platinum.
Exemptions
1. Any articles of gold, if manufactured before 1920 and of minimum fineness (375 parts per thousand [9 carat] or above) and that have not had any improper alterations.
2. Any article that is of the minimum fineness, but is too small or thin to be hallmarked.
3. Any article that is of minimum fineness and weighs less than the following table:
Gold.........1 gram
Silver.........5 grams
Platinum........0.5 grams
4. The following articles of gold if manufactured before 1 st January 1975, and of minimum fineness:
I. rings (except wedding rings),
II. articles made solely of filigree work,
III. articles so heavily engraved or set with stones that it is impossible to mark them without damage.
5. Any article which is wholly or mainly made from platinum, and which was manufactured before 1st January 1975.
For pearls, do the tongue test; run the pearl across the tip of your tongue and if the pearl feels gritty, it is probably real. If it does not, it is almost certainly imitation. Majorica (imitation) pearls can also feel gritty, too, so be careful.
Obviously, the best way is to ask an expert, but garnets and cubic zirconia are less hard on Mohs' scale than rubies and diamonds (and rhinestones are much less hard, as they are made of glass), so the facet edges will often look less sharp.
For more information:
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