桃園親子教育博物館二

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Calcite, which gets its name from "chalix" the Greek word for lime, is a most amazing and yet, most common mineral. It is one of the most common minerals on the face of the Earth, comprising about 4% by weight of the Earth's crust and is formed in many different geological environments. Calcite can form rocks of considerable mass and constitutes a significant part of all three major rock classification types. It forms oolitic, fossiliferous and massive limestones in sedimentary environments and even serves as the cements for many sandstones and shales. Limestone becomes marble from the heat and pressure of metamorphic events. Calcite is even a major component in the igneous rock called carbonatite and forms the major portion of many hydrothermal veins. Some of these rock types are composed of better than 99% calcite. Why would a collector be interested in such a common mineral? Because of its extraordinary diversity and beauty!

With calcite so abundant and so widely distributed it is no wonder that it can be so varied. The crystals of calcite can form literally a thousand different shapes by combining the basic forms of the positive rhombohedron, negative rhombohedron, steeply, moderately and slightly inclined rhombohedrons, various scalahedrons, prism and pinacoid to name a few of the more common forms. There are more than 300 crystal forms identified in calcite and these forms can combine to produce the thousand different crystal variations. Calcite also produces many twin varieties that are favorites among twin collectors. There are also phantoms, included crystals, color varieties, pseudomorphs and unique associations. There simply is no end to the varieties of calcite.

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　　上述原文說明方解石成份為碳酸鈣 CaCO3 含量佔地殼的大約４％，雖次於長石與水晶家族，但其多變性卻所向披靡，使得她有一千多種名稱及300多種結晶形狀，被稱之為沒有盡頭的品種。

　　國內方解石知名的收藏家靈芝先生，曾經送給敝小館精美的方解石標本。鐘乳石是方解石的一種產狀，國內收藏最豐富的是晶鎮水晶周小姐。

　　方解石比水晶或玉髓類更容易是螢光礦物，主因是方解石的形成環境為鹼性，在此條件各種金屬正離子除了鉀、鈉...等鹼金屬之外，更容易與碳酸根結合，反之如海水酸化則貝殼、珊瑚....將全部無法存活。隨著微量元素的不同，方解石呈現的螢光顏色也不同，例如臺灣的方解石螢光多為金黃色，其他地方常見的有粉紅色，上面是捷克的標本，相片顯出偏向紫色，國內知名礦物收藏家鮪魚先生來函，指係粉紅色的可能較高，我在收到標本檢查之後確定是紫色。