A key is divided into four "9 bars" each weighing 9 ounces. But, a key is a metric measure and a 9 bar an imperial one. Discrepancies occur and it is usual only to be guarenteed 8 1/4 ounces when you buy a 9. Good price for a 9 = £400. Bad price for a 9 = £810.
A 9 bar splits into nine ounces - an ounce is known as an Oz. Good price for an oz = £60. Bad price for an oz = £90. Price for skunk = £140.
An oz can be split into "halves", "quarters" (vicar's daughter), "eighths" (a Henery - so called after Henery VIII)and "sixteenths" (a Louie - after Louie XVI). An Oz may even be sold in grams.
Good price on a half = £45. Bad price = £55.
Good price for a quarter = £20. Bad price = £30.
Goob price on a eighth = £8. Bad price = £15.
Good price on a teenth = £5. Bad price = £7.50p.
Price for a gram = £5.
The stuff comes in a clear plastic heat proof sleeve and can be wrapped up to 4 times.Usually each bar has a stamp pressed into it for rough identification.The 9bars are usually pressed with a hydraulic jack to produce a shiny surface on the bar.
Each bar usually has 3 slits cut into it going length ways along the bar there are many reasons given for this. One of the more credible explanations for them is that they are made with a gardeners 3 pronged trowel which is used to pick them up while they are still warm and soft before grouping the 4x9bars into kilo bundles.