When I started collecting old alabaster lamp bases, I knew most of them would need a bit of work. What I hadn't quite anticipated was how difficult it would be to find a genuinely useful, step-by-step guide to restoring them.

There is plenty of information about alabaster, and plenty about conservation, but very little aimed at someone standing at a table with a yellowed old lamp wondering what exactly to do next.

Having now spent far more hours refurbishing alabaster than I ever imagined I would, I understand why. It is not the easiest material to work with.

Alabaster is an incredibly soft and porous stone. It marks easily, scratches easily and absorbs grease and dirt from years of handling. It also means that some of the usual instincts you might have when cleaning stone aren't necessarily helpful here.
So this is less a definitive restoration guide and more a record of what I did, what worked for me, and an insight into the patience you will need to try it!

Starting gently

Starting with the basics, I removed any loose dust with a very soft cloth and brush. It sounds almost too obvious, but with old pieces there is no point introducing anything stronger until you've taken away what will come off easily.

This only gets you so far.

The bases I had bought had accumulated years of grime, handling and some had quite significant yellowing. I used white spirits on a soft, lint-free cloth, working gradually across the surface rather than soaking the stone. It is really important to note that you don't use water on Alabaster.

For smaller details and awkward areas, something as simple as a wooden toothpick was surprisingly useful.

One thing I learned very quickly is to be careful when handling cleaned alabaster. Because the stone is so porous, oily or greasy fingerprints can mark it again remarkably easily. 

Gloves and a mask are useful for the amount of dust that will be generated from sanding.

Dealing with deeper yellowing

Some of the lamps cleaned up well at this stage.

Others didn't.
My most substantial one had a deep yellow cast that sat within the surface rather than on top of it. Further research suggested a technique of applying a thick poultice of bicarbonate of soda and white spirits to help draw out some of the ingrained staining. Place your stone and poultice in a clear plastic bag for 24 hours (remember white spirits will dissolve print, so be careful of this). Close the bag tightly in order not to dissolve the liquid and wait!

It did improve it, but it didn't completely solve it.

At that point I had to decide whether to live with the discolouration or start sanding layers off the surface.

At this stage, I wasn't giving up, and this is where the job became considerably more involved.

Sanding alabaster

Everything I read recommended being extremely cautious because alabaster is so soft.

Ideally, you want to begin with as fine an abrasive as possible. I first tried around 600 grit, but on this particular base it simply wasn't cutting through the yellowed surface.

Eventually I had to go coarser.

I went down to roughly 300 grit in some areas, which is much more aggressive than I would have liked and certainly not where I would automatically begin on another piece. But the staining on this one was particularly stubborn.

From there, it became a very slow process of working back through progressively finer grades.

Use foam-backed abrasive paper or sanding pads. A flat sheet of sandpaper is surprisingly awkward on a lamp base because so much of the shape is curved. The softer backing allows you to follow the contours without digging into one particular area. One of the most useful things I discovered was that fine emery boards were handy around tighter curves and details.

The important thing was not to push hard.

I found it much better to let the abrasive skim across the surface rather than trying to grind down into the stone. Alabaster will tell you very quickly when you're being too aggressive — scratches appear almost instantly.

And then you keep going.

And going.

And going.

The bit that makes it worthwhile

This is the best part.

Restoring one badly yellowed lamp took me hours and hours over the course of a couple of days.

But once the yellow surface began to disappear, the alabaster underneath was extraordinary.

The veining became clearer, the colour softened and sections of the stone became almost translucent. It has this beautiful combination of cloudy, opaque areas running into clearer veins that catch the light completely differently.

It is much more delicate-looking than marble and, particularly when it is illuminated, you begin to understand exactly why alabaster has been used for lighting for so long.

As I worked through the finer grades — eventually moving through 1200, towards 2000 grit — the surface became smoother and the stone started to regain its soft sheen.

It is definitely not a high, artificial polish. Just enough to bring the material back to life.

Finishing the stone

Once I was happy with the surface, I finished the bases very lightly with Renaissance Wax.

This came up repeatedly in my research and is widely used as a conservation wax on objects and furniture. A tiny amount goes a very long way.

I have also read about people using pure beeswax on alabaster, although I haven't tried that myself yet, so for these lamps I stayed with the Renaissance Wax.

The finished bases aren't meant to look brand new.

That wasn't really the point.

I wanted to remove the heavy staining and grime while still allowing them to feel like old pieces. There are small marks, tiny irregularities and evidence of their age, which is actually the point.

What has changed is that you can see the alabaster again.

And for me, that is where the beauty of these lamps really lies.

A note before trying this yourself

This is simply the process I used on the vintage lamp bases I was working with, rather than professional conservation advice. Alabaster varies enormously and valuable pieces are best left to a specialist.

Solvents also need to be used carefully, with good ventilation, gloves and the appropriate mask where necessary, and I would always test any cleaning method on an inconspicuous area first.

The biggest lesson I've learned is to start gently. You can always do more. With alabaster, undoing something is considerably harder.