Although amber is used in jewellery the same way stones like diamonds and emeralds are, Baltic amber is softer and more brittle than those types of jewels. It is not a mineral at all, but is a fossilised tree sap or resin. Baltic amber is not only one colour. Amber ranges in colour shade from pale yellows to browns, whites and greens or mixed colours. Found in the ground and along the shores of the Baltic Sea, amber may even contain the fossilised remains of ancient insects.
Choose the method of sanding you will use for sanding and polishing your piece of Baltic amber. Amber is a softer material so it can be hand-sanded if you prefer working with your hands and choose not to use power tools. This method will take longer than power sanding.
File or power-sand off the edges of the amber to the shape you want the finished amber piece to be (a cabochon shape, for example). You are rounding the sharpest edges and doing the final shaping in preparation for the high polishing.
Use a rough grade sandpaper of 80 to 160 grit and sand the surface of the amber after you file the piece of Baltic amber. You are removing the rough texture of the cut piece of amber.
Choose a fine-grade finishing sandpaper to use by hand or on the machine. Go over the piece completely and make sure you sand the whole surface of the amber thoroughly. This removes the rougher scratches made by the lower-grade sanding paper.
Use a cotton buffing wheel with a finishing compound to complete the shine on the finished piece of amber. Apply the compound to the piece of amber and polish the whole piece, removing the last of the scratches. Repeat with more compound if you need to. If you find spots that need more work after you finish this step, go back to a rougher sanding and work up to the final step again.
Polish a finished piece of Baltic amber by using a soft cloth and lukewarm water. You can also use a bit of olive oil and a soft cloth to clean and return the finished shine to the polished piece after you have washed it off. Rub the oil over the amber and wipe off the excess.
Baltic amber is a very soft material. It can chip and break when you work with it. It can also discolour if you use a strongly coloured polishing compound when buffing it.
Be careful when working with sanding and buffing wheels. Hold the piece you are working on tightly and down at the bottom of the wheel so it is less likely to grab the piece and throw it or catch your fingers.