4. Revenue Recognition (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues	$ 2,091,725	$ 2,369,714	$ 6,781,001	$ 7,827,525
Antimony [Member]
Revenues	1,366,540	1,796,776	4,540,873	5,860,584
Zeolite [Member]
Revenues	653,365	494,694	2,026,605	1,723,120
Precious Metals [Member]
Revenues	71,820	78,244	213,523	243,821
United States
Revenues	1,876,218	2,208,417	6,151,068	7,284,803
Canada
Revenues	215,507	161,297	629,933	542,722
Mexico
Revenues	$ 2,091,725	$ 2,369,714	$ 6,781,001	$ 7,827,525