The only way your contacts will be on SD is if you used the "export" option of your contacts app, which saves them as a vcard file on SD. If you did that, then the "import" option will reload them.
Otherwise they are stored on the phone in /data/data/com.android.providers.contacts/databases/contacts2.db, backed-up to the cloud if you have selected to sync them with Google. That local path I've given is only accessible to you if your device is rooted.