
Every time you work with or carry a crystal, it not only provides beneficial therapeutic value (please read Crystal Therapy Series - Part 1 - Introduction: What Is Crystal Therapy?), but also accumulates energy from its environment such as your emotions, thoughts and of those around you.
It is great for the crystal if you are having an awesome day in a harmonious environment and feel really good, but not so much if you are working through issues, feel emotional. or are perhaps spending time in a tense or stale environment at home or at work.