Silk is a natural fibre. It is a very luxurious fibre and will last a lifetime. But you do have to look after it properly.
It is best to wash a silk scarf with a soft - non-alkaline - detergent, such as baby soap or soft soap. Wash the silk scarf by hand and in water that is not warmer than 30 °C. Wash it carefully in soapy water, and do not rub or wring out. Rinse carefully but thoroughly using lukewarm water. Hang your scarf outside to dry or lay it down flat on a towel, so that it keeps its shape. Never put silk scarves in the tumble dryer! Ironing is best done when the scarf is still slightly moist, and at a low setting. Many irons will have a special ‘silk’ setting.
You can also take your silk scarf to the dry cleaner’s to have it professionally cleaned.