1
Whole & Broken Geodes!
0:58
2
Geode Field!
0:59
3
Botryoidal cut!
0:58
4
Shaping!
0:55
5
Opalized wood!
0:59
6
Broken Thunderegg Cluster!
0:35
7
Half a thunderegg!
0:52
8
Thunderegg Cluster w Common Opal!
0:41
9
Red Thunderegg Shard!
0:42
10
Robbed! Grabbed the wrong half!
0:59
11
Thunderegg Cut w/Opal!
0:59
12
Thundereggs?
0:59
13
Thundercup glow!
0:53
14
Thunderegg glow!
0:50
15
Beautiful dark opal!
0:31
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It's curved!
0:39
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Botryoidal formations!
0:32
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Jasper, Chalcedony, Opal & ???
0:52
Chalcedony or Opal!?
0:31
20
Clear/White Banding!
1:02
21
Thunderegg twins!
0:59
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Beautiful Opal Glow!
0:37
24
Opal or Chalcedony?
0:17
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Botryoidal!
0:18
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Some green!
0:16
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Botryoidal Mini Cave!
0:18
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Beautiful Bright Green!
0:23
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Opal?
0:17
30
Pretty green!
0:19
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Love the red!
0:31
32
Chalcedony or Opal?
0:19
33
Lil' bit of opal!
0:19
34
Opal!
0:27
35
Opal or Chalcedony?
0:24
36
Chalcedony & Jasper!
0:30
37
Part of a Thunderegg!?
0:35
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Pinks & Reds!
0:38
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Half a Thunderegg w/Opal!
0:38
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Botryoital Opal w/ A Little of Everything!
0:46
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Beautiful! Wait for it!!!
1:01
42
Thunderegg Cluster!
0:48

Chalcedony or Opal!?

6 months ago
21

#Chalcedony is a cryptocrystalline form of silica, much like chert, but it's distinguished by its fibrous microcrystalline structure. Here are the key features of chalcedony:

Composition:

Silica (SiO₂): Like chert, it's primarily composed of quartz, but the structure of the crystals is different.

Texture and Structure:

Microcrystalline: The individual crystals are too small to be seen with the naked eye.

Fibrous: Chalcedony often displays a fibrous or acicular (needle-like) structure in contrast to the more blocky or mosaic structure of other quartz varieties like chert.

Varieties of Chalcedony:

Agate: Known for its banded or layered appearance; each band often has a slightly different color.

Jasper: Similar to chalcedony but typically more opaque and can contain significant impurities like iron, giving it a wide range of colors.

Onyx: Usually refers to chalcedony with parallel bands of black and white, though the term can be misused for other banded chalcedonies.

Carnelian: A reddish variety due to iron oxide impurities.

Chrysoprase: Colored green by nickel silicate inclusions.

Bloodstone (Heliotrope): A dark green chalcedony with red spots of iron oxide or hematite.

Physical Properties:

Hardness: 6.5 to 7 on the Mohs scale, slightly softer than quartz but still quite durable.

Luster: Waxy or greasy when polished.

Transparency: Can range from translucent to nearly opaque.

Fracture: Conchoidal, similar to chert, but due to its fibrous nature, it can show a splintery fracture in some cases.

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