hi 소중하다 use when you want to say precious thing ex. this wedding ring is precious for me(이 결혼반지는 나에게 소중합니다) and 중요하다 means important

고마워요 :)

I would say "소중하다" is used when talking about something personal (ex. 이건 저에게 소중한거에요(=this is precious thing to me), 제겐 소중한 거니까 조심히 옮겨주세요 (=please carry it carefully because it is precious thing to me)). And "중요하다" is often used when talking about business or something not personal (ex. 이건 국제적으로 중요한 문제입니다(=this is internationally important matter), 이건 그가 그곳에 있었다는 중요한 증거입니다 (this is important evidence which proves that he was there)).

소중하다 is usually about your heart 중요하다 is usually about your mind 중요하다 has a wider range than 소중하다