Post by sparkles on Nov 17, 2008 15:59:18 GMT -5
Hiya Folks!
I was lucky enough to have the opportunity to cut a couple of these little beauties when a great friend of mine sent me a couple to try, and the results are here for you to see. I’m incredibly lucky to have such wonderful and generous friends, and I owe them a tremendous debt of thanks for the pleasure I have enjoyed. You know who you are!!! Thanks Buddy! ;D ;D ;D
Formed in rich Basaltic lavaflows some 130 million years ago, the unmistakable Oco Geodes are a favourite among cutters collectors and enthusiasts. Found in a variety of colours from dark almost black through grey and tan to a pale cream colour, the swirly white flames in the Chalcedony are characteristic of this type of formation. They range in size from around 5cm to about 20cm, and can show various forms of mineral growth inside, from the fine sparkly druze to fantastic rock crystals, and in more rare examples Amethyst crystals too. The name Oco is thought to be a reference from a Portuguese term for hollow, and may be the common name used to describe them by the locals that find and collect them. The “shell” of the geode is said to resemble a coiled rope, although personally, I think they look like Dragon Eggs!
The Geodes are collected by hand from the rich soils in and around the region of Tres Pinheiros, Brazil ( maps.google.com/maps?f=q&hl=en&geocode=&q=Tres+Pinheiros+brazil&sll=-28.6448,-52.676697&sspn=0.643581,0.884399&ie=UTF8&ll=-29.083551,-52.339039&spn=0.020027,0.027637&t=h&z=15&g=Tres+Pinheiros+brazil ) where the geodes have weathered out of their base rock and are found loose in the plough soil. Vast numbers of Oco Geodes are traded down the valleys and through the many merchants and dealers in to the nearby town of Soledade, a centre of mineral working and exchange.
The following rocks were sliced open on the 7in tile saw, and then ground and polished on my little 6in lap. I had no trouble with the trimming, although I found that one of the Geodes had been “open to the elements” and had grotty gunk on it’s crystals, this was remedied with plenty of warm soapy water and a delicate application of an old toothbrush! ;D
The first example produced this fabulous crystal cave, and the amazingly fine crystal growth was spectacular in both halves. The Agate was a little cracked and flawed but I was really happy with the two halves.
The second geode was an odd looking rock, and after deciding on the cut and opening it up, I was initially disappointed with the slightly grotty looking interior. However, I took the electric toothbrush to it and gave it a blitzing, and lo and behold the crystals appeared, and then I noticed, the crystals were actually pale Amethyst, but only in half of the geode. I was overjoyed! What a fabulous find! ;D
And my special friend who was so generous in the first instance gifted me a final treasure. This half geode has the most amazing crystal growth in the centre, and is just magnificent when you see it up close. The Agate is thicker and so it took a beautiful polish and I’m really chuffed with the result. Hope you agree - it’s a keeper! ;D
So between the combination of Lesley's tremendous generosity and an hour or two on the wheels of steel, and my collection of Oco Geodes is growing very nicely! Thankyou!
Hope you enjoyed the tour - it’s taken a while to complete this little project - but I’ve had such fun doing it! This place rocks! Thanks again,
Cheers,
Sparkles.
I was lucky enough to have the opportunity to cut a couple of these little beauties when a great friend of mine sent me a couple to try, and the results are here for you to see. I’m incredibly lucky to have such wonderful and generous friends, and I owe them a tremendous debt of thanks for the pleasure I have enjoyed. You know who you are!!! Thanks Buddy! ;D ;D ;D
Formed in rich Basaltic lavaflows some 130 million years ago, the unmistakable Oco Geodes are a favourite among cutters collectors and enthusiasts. Found in a variety of colours from dark almost black through grey and tan to a pale cream colour, the swirly white flames in the Chalcedony are characteristic of this type of formation. They range in size from around 5cm to about 20cm, and can show various forms of mineral growth inside, from the fine sparkly druze to fantastic rock crystals, and in more rare examples Amethyst crystals too. The name Oco is thought to be a reference from a Portuguese term for hollow, and may be the common name used to describe them by the locals that find and collect them. The “shell” of the geode is said to resemble a coiled rope, although personally, I think they look like Dragon Eggs!
The Geodes are collected by hand from the rich soils in and around the region of Tres Pinheiros, Brazil ( maps.google.com/maps?f=q&hl=en&geocode=&q=Tres+Pinheiros+brazil&sll=-28.6448,-52.676697&sspn=0.643581,0.884399&ie=UTF8&ll=-29.083551,-52.339039&spn=0.020027,0.027637&t=h&z=15&g=Tres+Pinheiros+brazil ) where the geodes have weathered out of their base rock and are found loose in the plough soil. Vast numbers of Oco Geodes are traded down the valleys and through the many merchants and dealers in to the nearby town of Soledade, a centre of mineral working and exchange.
The following rocks were sliced open on the 7in tile saw, and then ground and polished on my little 6in lap. I had no trouble with the trimming, although I found that one of the Geodes had been “open to the elements” and had grotty gunk on it’s crystals, this was remedied with plenty of warm soapy water and a delicate application of an old toothbrush! ;D
The first example produced this fabulous crystal cave, and the amazingly fine crystal growth was spectacular in both halves. The Agate was a little cracked and flawed but I was really happy with the two halves.
The second geode was an odd looking rock, and after deciding on the cut and opening it up, I was initially disappointed with the slightly grotty looking interior. However, I took the electric toothbrush to it and gave it a blitzing, and lo and behold the crystals appeared, and then I noticed, the crystals were actually pale Amethyst, but only in half of the geode. I was overjoyed! What a fabulous find! ;D
And my special friend who was so generous in the first instance gifted me a final treasure. This half geode has the most amazing crystal growth in the centre, and is just magnificent when you see it up close. The Agate is thicker and so it took a beautiful polish and I’m really chuffed with the result. Hope you agree - it’s a keeper! ;D
So between the combination of Lesley's tremendous generosity and an hour or two on the wheels of steel, and my collection of Oco Geodes is growing very nicely! Thankyou!
Hope you enjoyed the tour - it’s taken a while to complete this little project - but I’ve had such fun doing it! This place rocks! Thanks again,
Cheers,
Sparkles.