Take two objects with a straight edge, preferably a butter knife and a sturdy piece of paper. Place the paper at the very edge of the stain, and gently scrape any loose pieces of chocolate with the butter knife onto the paper. Using the paper to catch the extra chocolate will help to prevent the stain from spreading. Once you are finished, carefully pick up the paper and discard it and the chocolate flecks.
Add a very small amount of laundry detergent, meant for delicate fabrics such as silk, to a small to medium sized bowel. Fill the bowl with warm water, making sure the detergent dissolves completely into the water.
Dip a clean, colorfast sponge or cloth into the warm, soapy water. Any sponge or cloth with dye in it can potentially bleed onto your silk chair, even if you have never noticed the same item transferring color during other cleaning tasks.
Dab the dampened sponge on a hidden spot on the silk chair to make sure the solution will not ruin the color or fabric. If it does, use another type of laundry detergent, mild hand soap or dilute the mixture even further with water and try again. You can also try using cold water if the solution seems to be removing the dye from the silk.
Dampen the sponge or cloth again once you have the proper mixture and gently dab at the chocolate stain on the silk chair. Do not rub the stain. This will push the chocolate farther into the fabric and potentially smear the stain, making it even more difficult to remove. Continue to dab at the stain until it disappears.
Dry the damp spot on the silk chair as quickly as possible without any type of heat. The best way to do this is to point a regular household fan at the stain and let it blow in that direction until the spot is dry. Do not use any type of drying method that involves heat, as this can cause the silk upholstery to constrict, potentially causing dimpling in the chair's fabric or making the area more prone to tearing.