4. Revenue Recognition (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues	$ 2,256,347	$ 2,838,480	$ 4,689,276	$ 5,457,811
Antimony [Member]
Revenues	1,492,520	2,077,300	3,174,333	4,063,808
Zeolite [Member]
Revenues	682,534	616,414	1,373,240	1,228,426
Precious Metals [Member]
Revenues	81,293	144,766	141,703	165,577
United States
Revenues	1,878,244	2,653,227	4,125,935	4,950,282
Canada
Revenues	$ 378,103	$ 185,253	$ 563,341	$ 507,529