Imagine you are handed a mineral sample. it breaks with a conchoidal fracture, but displays no cleavage. it does not react with hydrochloric acid, is a light pink color, and has a nonmetallic luster. it is harder than a streak plate, and has a specific gravity of 2.65. what mineral is it?

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.