Tidgy's Dad Posted December 19, 2017 Posted December 19, 2017 Looks like sandstone to me, but it has been compacted and slightly metamorphosed so that some of it, the sort of grey areas, have recrystallized the original quartz grains of the matix into a quartzite. 1 Life's Good! Tortoise Friend.
hauyn888 Posted December 19, 2017 Posted December 19, 2017 For the first moment I thought sandstone, quartzite and quartz quartz so agree Tidgy´s Dad too -if it will be metamorphosed I don´t know or in a second step perhaps silicic acid-leading water (possibly hydrothermal) was fed - so you could explain the red bands - hematite too 1
ynot Posted December 19, 2017 Posted December 19, 2017 I see an iron staind sandstone with a quartzite (chert, flint) nodule in it. And the print of a clam shell in the fourth picture. 2
Miocene_Mason Posted December 19, 2017 Posted December 19, 2017 Yeah quartzite, reminds me of the oriskany quartzite at the sandy mile site (west Maryland, though I believe it outcrops in several places on the east coast). Is has brachiopod impressions as well as Gastropods and crinoids. tends to be in a white matrix though. Iron has stained this one as others have pointed out. Happy hunting, Mason
ynot Posted February 10, 2018 Posted February 10, 2018 24 minutes ago, Malone said: It kinda looks like feldspar crystal Wrong shape and no cleavage visible. Not a crystal- feldspar or other.
Malone Posted February 10, 2018 Posted February 10, 2018 1 hour ago, ynot said: Wrong shape and no cleavage visible. Not a crystal- feldspar or other. In the first picture the straight cleavage on the left side of the rock. Orthoclase? Plagioclase? The straight cleavage is an indication of the crystal structure similar to feldspar. Almost all rock is crystalline in some form.
Malone Posted February 10, 2018 Posted February 10, 2018 It may be just fractured but that's the same with feldspar
ynot Posted February 10, 2018 Posted February 10, 2018 2 hours ago, Malone said: In the first picture the straight cleavage on the left side of the rock. Orthoclase? Plagioclase? The straight cleavage is an indication of the crystal structure similar to feldspar. Almost all rock is crystalline in some form. A straight fracture is not necessarily a cleavage. Many crystals will have a cleavage, You have to look at how many cleavage planes there are and what angle(s) between the cleavage planes. Just because a rock is "crystalline" does not make it a crystal, and only certain crystals have a defined cleavage structure. 2 hours ago, Malone said: It may be just fractured but that's the same with feldspar Feldspar has such a well developed cleavage that it will fracture along the cleavage planes when it breaks. I see no evidence of a cleavage in the OP's piece. . 1
Malone Posted February 10, 2018 Posted February 10, 2018 15 minutes ago, ynot said: A straight fracture is not necessarily a cleavage. Many crystals will have a cleavage, You have to look at how many cleavage planes there are and what angle(s) between the cleavage planes. Just because a rock is "crystalline" does not make it a crystal, and only certain crystals have a defined cleavage structure. Feldspar has such a well developed cleavage that it will fracture along the cleavage planes when it breaks. I see no evidence of a cleavage in the OP's piece. . You have it down better than me. I was looking into rock that broke into those shapes and came across feldspar. There are so many names for rock. without a gas chromatograph it's difficult to get the most defined name. Thank you for helping me be more concise. I really am a novice who likes to join in on interesting conversation.
Malone Posted February 10, 2018 Posted February 10, 2018 This is what I had researched and thought it was the same.
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