Nature and Secrets

Across

1. Pertaining to ships or the navy

3. Release of gas or light energy

6. African antelope known for migrations

8. British treasury department managing funds

9. Dim light before nightfall

10. Difficult to explain or understand quality

Down

2. Able to be seen clearly

4. Philosophy focusing on nature and reality

5. Free promotional item or reveal

7. Volcanic event causing lava flow