Rayon or artificial silk is much less costly to produce and can be produced in larger quantities than natural silk as there are not worms but machines involved. The artificial silk is a synthetically manufactured material.

Natural silk is a fiber gathered from the cocoon of the silk worms. The natural glue, sericin, secreted by silkworms is not removed during manufacturing of the silk. Most silk fabrics can be hand washed. A garment made of silk is very comfortable and is specially good for moderate seasons. There are many types of silk. Brocade, canton crepe, chiffon, silk linen, silk satin etc.

Rayon is strong, is extremely absorbent, comes in a variety of qualities and weights, and can be made to resemble natural fabrics. Rayon does not melt but burns at high temperatures.

If you are worried that the silk you are purchasing is not pure then there are a number of tests that you can do to check the authenticity of the material. The most easy is the burn test. Burn the fiber that you have. If the smell is like burning hair and the ash which accumulates is easily dispersed, then the material is likely to be pure silk. Rayon, on the other hand, is a regenerated cellulose fiber which is almost pure cellulose. Rayon burns rapidly and leaves only a slight ash. The burning smell is close to burning leaves.