Cal. Insurance Code § 10088

Notwithstanding the provisions of Section 530, 532, or any other provision of law, and in the absence of an endorsement or an additional policy provision specifically covering the peril of earthquake, no policy which by its terms does not cover the peril of earthquake shall provide or shall be held to provide coverage for any loss or damage when earthquake is a proximate cause regardless of whether the loss or damage also directly or indirectly results from, or is contributed to, concurrently or in any sequence by any other proximate or remote cause, whether or not covered by the policy. The term “policy” as used in this section includes all policies of any nature, including, but not limited to, business and commercial forms providing coverage against loss due to damage to the property of the insured. Nothing in this section shall operate to affect the provisions of Section 2071 or preclude an insurer from specifically providing coverage for direct loss caused by explosion, theft, or glass breakage resulting from an earthquake.