These would look great on your coffee table: Paddywax Small Concrete Candles
DIY Concrete Candlestick Tutorial from DIY Candy. This easy DIY uses plastic bottles and Quikrete (which I’ve used for stepping stones and have carved up into abstract sculptures).
Smilla's sense of living: DIY: Concrete candleholder / candlestick cement
Stackable Concrete Geometric Tea Light Candle Holder and Catch All Vessel (candels)
DIY geometrical candle shapes / via homemade-modern
Candle holders, made out of concrete. By pressing a candle in a plastic bag with liquid concrete, the folds in the plastic bag create a soft ‘pillow’ look on the surface of the concrete.
Single Concrete Tea-Light Candleholder by Marit Meisler for ceMMent