_Composition_: fossil resin. _Crystal system_: amorphous. _Hardness_:
about 2.0 to 2.5. _Specific gravity_: variable, from 1.05 to 1.10.
_Luster_: resinous. _Color_: brown, yellow, red, orange, and white.
_Streak_: white to yellowish to gray. _Cleavage_: none. _Fracture_:
conchoidal. _Tenacity_: brittle. _Diaphaneity_: transparent to
translucent. _Refractive index_: variable, about 1.54. Burns with a
sweet, piney odor.
Rich brown to yellowish amber has been found near Eagle Pass, Maverick
County, in Cretaceous coal and on Terlingua Creek, Brewster County.
Although much of this material is translucent and the quality suitable
for lapidary purposes, the pieces are seldom more than a fraction of an
inch in diameter.
Occasional finds of poor quality brownish amber have been reported from
the Tertiary formations of the Gulf Coastal Plain, but thus far no gem
quality material has been found.
The softness of amber limits its use to brooches, necklaces, and other
jewelry that is relatively safe from abrasion.