Thirty-three amendments to the United States Constitution have been proposed by the United States Congress and sent to the states for ratification since the Constitution was put into operation on March 4, 1789. Twenty-seven of these, having been ratified by the requisite number of states, are part of the Constitution. The first ten amendments were adopted and ratified simultaneously and are known collectively as the Bill of Rights. Six amendments adopted by Congress and sent to the states have not been ratified by the required number of states.
Learn about the crystal meanings and metaphysical and healing properties lore of calcite. Alternate Names & Name Spellings: Calcspar; Clear Calcite is sometimes called Optical Calcite or Iceland Spar or Iceland Crystals.
Calcite is the only common non-silicate rock forming mineral, being instead calcium carbonate. It has two refractive indices causing a significant double refraction effect - when a clear calcite crystal is placed on an image, a double image is observed; See the sample below. Calcite will fizz when dilute hydrochloric acid is placed on it. It may be fluorescent, phosphorescent, thermoluminescent and triboluminescent (see fluorite for definitions of these properties). Calcite is one of the most ubiquitous minerals, being an important rock forming mineral in sedimentary environments. It is an essential component of limestones, and occurs in other sedimentary rocks. It also occurs in metamorphic and igneous rocks, and is common in hydrothermal environments. Calcite is a common vein filling mineral in many rock types.