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Hypersthene - Canada Stone

Posted by Jacqueline Johnson on

Hypersthene - Canada Stone

Hypersthene Cabochon Hypersthene is a common rock-forming inosilicate mineral belonging to the group of orthorhombic pyroxenes. Its chemical formula is (Mg,Fe)SiO3. It is found in igneous and some metamorphic rocks as well as in stony and iron meteorites. Many references have formally abandoned this term, preferring to categorize this mineral as enstatite or ferrosilite. It forms a solid solution series with the minerals enstatite and ferrosilite, being a mid-way member between the two. Pure enstatite contains no iron, while pure ferrosillite contains no magnesium; hypersthene is the name given to the mineral when a significant amount of both elements are...

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Lake Michigan Pegmatite Cabochon

Posted by Jacqueline Johnson on

Lake Michigan Pegmatite Cabochon

Lake Michigan Pegmatite Cabochon

A pegmatite is an igneous rock, formed underground, with interlocking crystals usually larger than 2.5 cm in size (1 in). Most pegmatites are found in sheets of rock (dikes and veins) near large masses of igneous rocks called batholiths.

The word pegmatite derives from Homeric Greek, πήγνυμι (pegnymi), which means “to bind together”, in reference to the intertwined crystals of quartz and feldspar in the texture known as graphic granite.

Most pegmatites are composed of quartz, feldspar and mica, having a similar silicic composition as granite. Rarer intermediate composition and mafic pegmatites containing amphibole, Ca-plagioclase feldspar, pyroxene, feldspathoids and other unusual minerals are known, found in recrystallised zones and apophyses associated with large layered intrusions.

Crystal size is the most striking feature of pegmatites, with crystals usually over 5 cm in size. Individual crystals over 10 metres (33 ft) long have been found, and many of the world's largest crystals were found within pegmatites. These include spodumene, microcline, beryl, and tourmaline.

Similarly, crystal texture and form within pegmatitic rock may be taken to extreme size and perfection. Feldspar within a pegmatite may display exaggerated and perfect twinning, exsolution lamellae, and when affected by hydrous crystallization, macroscale graphic texture is known, with feldspar and quartz intergrown. Perthite feldspar within a pegmatite often shows gigantic perthitic texture visible to the naked eye. The product of pegmatite decomposition is euclase.

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Lake Michigan Stone Knobs

Posted by Jacqueline Johnson on

Lake Michigan Stone Knobs

mg src="https://cdn.shopify.com/s/files/1/1528/7517/t/19/assets/lake-michigan-stone-knobs_7189.jpg" alt="Lake Michigan Stone Knob - Stone Treasures by the Lake" data-original="https://cdn.shopify.com/s/files/1/1528/7517/files/E1AA1DF1-F692-45F1-9835-D6DF0FAF5B21_large.jpeg?v=1539962318"

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Merry Christmas

Posted by Jacqueline Johnson on

Merry Christmas

Merry Christmas! - See the variety of designer cabochons available: Lake Michigan Stones, Petoskey Stones and many more. Merry Christmas and Happy New Year!

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Glass Buttes Fire Pit Obsidian

Posted by Jacqueline Johnson on

Glass Buttes Fire Pit Obsidian

Glass Buttes Fire Pit Obsidian Slab Glass Buttes are a group of volcanic mountains consisting of two prominent peaks and several smaller hills. They are located in the remote northeast corner of the Lake County between Bend and Burns in central Oregon, United States.  The buttes are an important landmark in an area once known as the Oregon’s Great Sandy Desert. They are named for the numerous large deposits of obsidian found on their slopes. Today, most of the mountains and surrounding land are administered by the Bureau of Land Management. The mountains offer a number of recreational opportunities including rock collecting,...

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