Mineralogy Quick Quiz Pictures
Another familiar sample that people new to mineralogy sometimes confuse with calcite is below. This mineral crystallizes at much higher temperatures than calcite, but at lower temperatures relative to other silicates.
Here is a closer look at the picture above
You may be more used to seeing that mineral, quartz, as euhedral crystals such as those below
The next mineral occurs in most igneous rocks as well as often occurring in marbles and metamorphic rock¹. More often microscopic, the sample below is big enough to be from a pegmatite, being over 3 cm across. It is harder than calcite and is softer than quartz.
[1] John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, and Monte C. Nichols, Eds., Handbook of Mineralogy, Mineralogical Society of America, Chantilly, VA 20151-1110, USA. http://www.handbookofmineralogy.org/.
