Non-silicates constitute less than 10% of the Earth's crust. The most common non-silicates are the carbonates, the oxides, and the sulfides. There are also naturally occuring phosphates and salts. There are a few elements which occur in pure form, including gold, silver, copper, bismuth, arsenic, lead and tellurium.Carbon is found in both graphite and diamond form.he most common minerals are the silicates, as one would guess by looking at the abundances of the elements in the Earth's crust, but there is a great variety of minerals. Minerals are classified in many ways, including hardness, optical properties, crystal structure, etc.
Vas deferens: The tube that connects the testes with the urethra. The vas deferens is a coiled duct that conveys sperm from the epididymis to the ejaculatory duct and the urethra.
For further discussion of the vas deferens within the context of the structures and functions of reproduction and sexuality, please see the overview section âThe Reproductive System.â. See also FERTILITY; TESTICLES; VASECTOMY.