The workshops teach you how to create your own jewellery, it costs 25 Euros per person (unless you're under 11 years old in which case it only costs 17.50 Euros). It includes all materials plus drinks and snacks. There is no minimum amount of participants and it's possible to book any time of the week during business hours. Sounds like a great way to spend time with friends to me!
Images: ℅ Lucie's Amsterdam website / Facebook page / Pinterest