electrine

from The Century Dictionary.

• Belonging to or made of amber.
• Composed of the alloy called electrum (which see).
• noun The (supposed) principle of electricity; a (supposed) kind of matter which manifests electrical phenomena.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Belonging to, or made of, amber.
• adjective Made of electrum, an alloy used by the ancients.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Of or pertaining to amber (especially having the ability to generate static electricity)
• adjective Of of pertaining to the alloy electrum