To be effective, a power of attorney by a depository account holder to manage or withdraw precious metals from the depository account holder's depository account must be notarized. Powers of attorney shall be effective for the length of time designated on the form unless earlier revoked by the depository account holder in writing or upon written notice of the death or adjudication of incompetency of the depository account holder.
34 Tex. Admin. Code § 14.13