What are the elements of the crime of extortion?

"Extortion is the obtaining of property from another, with his consent, . . . induced by a wrongful use of force or fear . . . ." ( 518.) A person who tries, by means of such a threat, to extort money or other property from another is guilty of attempted extortion. ( 524.) "The elements of the crime of attempted extortion are (1) a specific intent to commit extortion and (2) a direct ineffectual act done towards its commission." (People v. Sales (2004) 116 Cal.App.4th 741,749.) "Preparation alone will not establish an attempt. There must be '"some appreciable fragment of the crime committed [and] it must be in such progress that it will be consummated unless interrupted by circumstances independent of the will of the attempter . . . ."'" (Ibid.)