The rich green variety of beryl. Often mentioned in the Bible but never 'definitely identified. When fossilization takes place a substance or the image of a substance is preserved for us by being buried for a long time in solid rock or in some other hard earthy substance. When hydrous sulfate of lime occurs in crystalline and transparent form it is sometimes called selenite. When it is finely grained and of variegated color it is called alabaster.
Satin spar comes almost exclusively from Russia.
There is an abundance of gypsum found in the grotto. This is an unusually good specimen of iron ore which contains mica. Various colored kinds are found in the Grotto. Nephrite is a silicate of magnesia and very tough. Jadeite is a variety of the same composition but softer than nephrite.