Selenite (mineral) was filled with mineral-rich water that drove the crystals' growth. The largest of those crystals weighs 55 tons, is long, and is over 500,000 years old. Gypsum occurs on every continent and is the most common of all the sulfate minerals. Gypsum is formed as an evaporative mineral, frequently found in alkaline lake muds, clay beds, evaporated seas, salt flats, salt springs, and caves. It is frequently found in conjunction with other minerals such as, copper ores, sulfur and sulfides, silver, iron ores, coal, calcite, dolomite, limestone, and opal. Gypsum has been dated to almost every geologic age since the
Interlanguage fossilization on interlanguage fossilization are fascinating in that they contradict our basic understanding of the human capacity to learn. How is it that some learners can overcome interlanguage fossilization, even if they only constitute, according to Selinker, "a mere 5%", while the majority of second language learners cannot, "no matter what the age or amount of explanation or instruction"? Or is it perhaps not that they cannot overcome fossilization, but that they will not? Does complacency set in after second language learners begin to communicate, as far as they are concerned, effectively enough, in the target language, and as a result