Chelsea Filter Digital scales - regular lines - resolution 0.1g That is why it is

That is why it is so difficult to tell them apart

longer working distances)

this applies to all simple lenses (i

despite its relatively low price

Focus range 1mm to 40mm

Chelsea Filter Digital scales - regular lines - resolution 0.1g That is why it isSummary The original Chelsea Filter, as developed at the Chelsea College of Science and Technology in 1934. Do not confuse this with the many copies. Detail Many stones appear to change colour when viewed through the filter. Originally designed for detecting synthetic emeralds, nowadays the Chelsea filter is an invaluable aid to identifying many other gemstones. It can give an indication that you have an emeralds and aquamarines, though not a