There are several different types of saws used to cut ceramic tile, but for all of these the best ceramic tile saw blades are those with a diamond edge. Diamond is the hardest known mineral, and is often used when a tool needs to be extremely hard and durable. Different saws use different sizes and styles of ceramic tile saw blades.
A typical full sized tile saw is equipped with a source of water to cool the cutting edge of the ceramic tile saw blades as they cut through the tile. The saw itself is arranged something like a table saw for wood, except the circular saw blade is pressed down from above to cut through the tile.
Needless to say, using this type of saw requires a great deal of care as well as protective eye goggles. Small pieces should be held by a clamp so that the worker's hands never get anywhere near the ceramic tile saw blades. Care should also be taken regarding the use of extension cords and electricity because of the water involved. Always read the instructions and follow them.
Portable ceramic tile saws also use diamond tipped ceramic tile saw blades, but these are generally only four inches in diameter. They are available in either a dry cutting version or one that is cooled by water. They are more versatile and less expensive than the standard saw, but do not provide the precision you can get with the standard tile saw.
One company that makes ceramic tile saw blades is DeWalt. These are advertised to have a high diamond concentration which makes the saw cut through the ceramic tile more quickly. These blades are also reported to have a long life. They feature a steal core that reduces vibration in the saw and cuts down distortion at high temperatures.
Technically, diamond tipped ceramic tile saw blades don't really cut. Instead, the edge is embedded with many tiny sharp diamonds which in effect grind their way through the tile. If the saw blade is the right one for the material being cut, it should stay sharp. If it is not a proper match between blade and material, the diamonds can become rounded off so that they don't grind anything anymore.
A method to sharpen the blade on a tile saw is to reduce the water to half and cut on an abrasive item like a concrete block or soft brick. After a number of passes, the dull diamonds should be removed and new sharp ones again on the edge.