At this time we do not have support for automatically tracking the value of precious metals and gems. In order to add the value of these assets to your account, you will need to create a Manual account:
1. Log in to Personal Capital
2. Click on the 'Link' (+) icon on the sidebar.
3. Click on 'More...'
4. Select the appropriate category (Jewelry, for example)
5. Enter a description and value then click 'Done'
As this is a manual account, you will need to update the value as it changes.