ANTIQUES: don't lose your marbles! Why these little round balls may be worth more than what you paid for them.
MY wife thought I'd lost them long ago but here's photographic proof: I've still got my marbles. The game of marbles has a very long history stretching back at least to Roman times.
There are many different versions, one of the most common being Ring Taw, which involves using a shooter marble to knock opponents' marbles out of a circle.
This has been played in Tinsley Green in Sussex since 1588, where they hold the Annual World Marbles Championship every Good Friday.
The first marbles were made of stone - marble, in fact. By the 17th century, stone marbles were being produced in Germany using water mills and from the mid 1800s to the early 1900s, considerable quantities of limestone marbles were being manufactured.
Clay marbles also have a long history, going back 400 years.
By the 1890s, they were being produced in industrial quantities in the US, the main centre being Akron, Ohio - it's estimated that more than three million marbles were being made there a day.
Because such large amounts were produced, bog-standard clay and limestone marbles are not particularly sought after today.
Most marble collectors - or "mibologists" - go for glass, which they divide into three categories: hand-made, machine-made and contemporary.
Most old hand-made glass marbles were made in Germany between 1860 and 1920.
Hand-made marbles can be identified by the presence of one or two pontil marks at the point where the molten glass was originally held on a rod.
Desirability is largely determined by type, based on pattern, style and colours, as well as by size and condition.
The most common are "swirls" - marbles with a swirled pattern - which are further sub-divided by type of core. Onionskins and End of Day marbles have designs made of stretched dots, while Lutz marbles are particularly prized.
These are striped with goldstone, or copper aventurine glass, usually highlighted with white.
Another very sought-after class of handmades is the sulphides.
These transparent marbles contain small porcelain figures, requiring great skill to produce.
The first machine-made marbles were made by MF Christensen in 1905.
By the 1920s, improvements in marble-making technology meant that machine-made marbles dominated the market with the US overtaking Germany as the main country of production.
Vintage machine-made marbles are becoming more and more collectible. The best-known companies are MF Christensen, the Christensen Agate Company, the Akro Agate Company and the Peltier Glass Company.
"Glowies" marbles contain small amounts of radioactive uranium oxide that fluoresce under ultra-violet or "black" light.
Cat's Eye marbles from the Far East, which flooded the market in the 1950s and 60s, are of no interest to collectors, although many of us remember playing with them. Nowadays, a high percentage of mass-produced marbles come from Mexico. An example of this is a bright blue marble with white swirls, a pattern which is called Tidal Wave.
New marbles are remarkably cheap.
You could buy a bag of 25 Tidal Waves for only pounds 1.50.
Although very rare marbles can sell for four-figure sums, most marbles are quite modestly priced. The more collectible examples I have are only worth 50p to pounds 5 each - not at all bad, considering I bought a bag of over 100 of them in an antiques fair for just pounds 4!
Marbles can fetch huge sums, with some selling for four figures