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.
Vas deferens: The vas deferens is a long, muscular tube that travels from the epididymis into the pelvic cavity, to just behind the bladder. The vas deferens transports mature sperm to the urethra, the tube that carries urine or sperm to outside of the body, in preparation for ejaculation.Ejaculatory ducts: These are formed by the fusion of the vas deferens and the seminal vesicles (see below). The ejaculatory ducts empty into the urethra.he internal organs of the male reproductive system, also called accessory organs, include the following: Epididymis: The epididymis is a long, coiled tube that rests on the backside of each testicle. It transports and stores sperm cells that are produced in the testes.