Chiseled live rock. INSIDE OF LIVE ROCK IS BLACK??

samstersam · 01/27/2007, 01:06 AM

I purchased Lalo rock from Liveaquaria. It was beautiful. Slightly bleached but I saw faint hues of pink and green and orange... When i touched the rock or handled it , i felt slight crisp micro-things crackle under my pressure...

Then I purchased LFS rock.; It was very heavy compared to the lalo. It was not as shapely but more varied tan to dark brown. I chiseled the rock and inside was a thin outline of the shape of the rock which was BLACK!

It looked like granite or something. Interested and I chiselled the center of lalo rock of similar size. It was pure white and felt porous...

Anyione have comments? These look like cheap atlantic rocks to me. Why is it black in the middle? The chisel was harder and harder to chisel in when it got blacker and blacker. The thin tan crust was easy to break through. I feel like I got ripped off, considering it was almost the same price as the lalo rock i got from live aquaria.

figuerres · 01/27/2007, 01:16 AM

color is related to the minerals the rock is made of and how porus it is...

anearobic pockets of sand and rock may turn black due to the types of bacteria that live in oxygen depleted areas....

now if you saw rust i'd worry -- that's iron
or green metalic stuff -- possible copper

but the chances of reef rock having copper are next to zero.
same for iron....

dga · 01/27/2007, 01:21 AM

i would think because of the density of the rock that it would not harbor as many good bacteria. and limited amount of surface area like more porus tonga and fiji due to there more open surface area...

samstersam · 01/27/2007, 01:22 AM

so what i'm seeing are possibly anoxic zones of the rock (i know what you mean by being black..had a DSB and when I took some sand out there were black areas.) that would de-nitrate? I guess now that they are aerobic these areas would turn tan to whitish?

samstersam · 01/27/2007, 01:25 AM

Or it could simply mean they are very dense granite or something like that. Like I mentioned, it DID get harder to chiselk the darker it got...

cheap rock eh?
I'm dumping some of them. The funny thing is cycling in my tank is a lalo 30 pounder and 5 pieces of the cheap LFS rock that add up to about 30 lbs. Some of the LFS rock are developing hair algae, but the lalo is beautiful.

pledosophy · 01/27/2007, 01:27 AM

That is some nice quality rock with that much anaerobic bacteria built in. Unfortunatley it's all dead now but wow, I wish I could get rock like that.

HippieSmell · 01/27/2007, 01:51 AM

The black is caused by sulfur deposits created from anoxic areas. It's not really bad, but it's because it's really dense rock. With rock, you're really buying surface area, and the Lalo is more porous than mined limestone, which may be what your LFS is selling.

jgoodrich71 · 01/27/2007, 08:28 AM

Quote:

Originally posted by samstersam
Or it could simply mean they are very dense granite or something like that. Like I mentioned, it DID get harder to chiselk the darker it got...

I can guarantee that is not granite. It is some type of limestone. It is possible, that since it is in the center, diagenisis could occur changing aragonite to calcite or just growth of larger aragonite crystals that account for the harder, more dense rock. But it is not granite, or any other igneous rock.

And as others have stated, the black is just another mineral. It is probably deposited due to the low oxygen environment in the rock. It is nothing harmful.

RedEyeElf · 01/27/2007, 09:19 AM

The diffrence really is, the LFS rock is probably cultured, and the Liveaquaria rock is from the ocean

Better bio-diversity in the non cultured stuff

Fenner talks alot about this in one of his books

I have seen lots of diffrent types of cultured rock, pretty sure liveaquaria sells some too
Atleast what my friend got from there sure looked like it came from Missouri, then sat in the ocean for acouple months...

01/27/2007, 01:06 AM	#1
samstersam Registered Member Join Date: May 2003 Location: NYC Posts: 389	Chiseled live rock. INSIDE OF LIVE ROCK IS BLACK?? I purchased Lalo rock from Liveaquaria. It was beautiful. Slightly bleached but I saw faint hues of pink and green and orange... When i touched the rock or handled it , i felt slight crisp micro-things crackle under my pressure... Then I purchased LFS rock.; It was very heavy compared to the lalo. It was not as shapely but more varied tan to dark brown. I chiseled the rock and inside was a thin outline of the shape of the rock which was BLACK! It looked like granite or something. Interested and I chiselled the center of lalo rock of similar size. It was pure white and felt porous... Anyione have comments? These look like cheap atlantic rocks to me. Why is it black in the middle? The chisel was harder and harder to chisel in when it got blacker and blacker. The thin tan crust was easy to break through. I feel like I got ripped off, considering it was almost the same price as the lalo rock i got from live aquaria.

01/27/2007, 01:16 AM	#2
figuerres Registered Member Join Date: May 2002 Location: Plant City,FL,USA Posts: 1,339 Blog Entries: 15	color is related to the minerals the rock is made of and how porus it is... anearobic pockets of sand and rock may turn black due to the types of bacteria that live in oxygen depleted areas.... now if you saw rust i'd worry -- that's iron or green metalic stuff -- possible copper but the chances of reef rock having copper are next to zero. same for iron.... __________________ Denny, Geek of all things... I guess I could fit the phrase "inquiring minds want to know..." :-) Current Tank Info: 150 reef tank underway, getting it stocked

01/27/2007, 01:21 AM	#3
dga Registered Member Join Date: Feb 2005 Location: MI Posts: 360	i would think because of the density of the rock that it would not harbor as many good bacteria. and limited amount of surface area like more porus tonga and fiji due to there more open surface area... __________________ Got Salt?

01/27/2007, 01:27 AM	#6
pledosophy Registered Member Join Date: Jan 2005 Location: Beaverton Posts: 5,290	That is some nice quality rock with that much anaerobic bacteria built in. Unfortunatley it's all dead now but wow, I wish I could get rock like that. __________________ 120g mixed reef 90g QT

01/27/2007, 01:51 AM	#7
HippieSmell Occupy Reef Central Join Date: Jun 2004 Location: Orbiting Posts: 4,141	The black is caused by sulfur deposits created from anoxic areas. It's not really bad, but it's because it's really dense rock. With rock, you're really buying surface area, and the Lalo is more porous than mined limestone, which may be what your LFS is selling. __________________ Time flies like an arrow. Fruit flies like bananas. Current Tank Info: 78"x36"x27" acrylic, 6 Orphek Atlantik V3+ Compacts, MRC Orca Pro II w/washdown, CalcFeeder Pro AC3, Emperor Aquatics 80w UV, 80/20 aluminum stand, Vortech MP60's, Theiling Rollermat, GHL Profilux 3.1T EX, Kessil H380

01/27/2007, 01:22 AM	#4
samstersam Registered Member Join Date: May 2003 Location: NYC Posts: 389	so what i'm seeing are possibly anoxic zones of the rock (i know what you mean by being black..had a DSB and when I took some sand out there were black areas.) that would de-nitrate? I guess now that they are aerobic these areas would turn tan to whitish?

01/27/2007, 01:25 AM	#5
samstersam Registered Member Join Date: May 2003 Location: NYC Posts: 389	Or it could simply mean they are very dense granite or something like that. Like I mentioned, it DID get harder to chiselk the darker it got... cheap rock eh? I'm dumping some of them. The funny thing is cycling in my tank is a lalo 30 pounder and 5 pieces of the cheap LFS rock that add up to about 30 lbs. Some of the LFS rock are developing hair algae, but the lalo is beautiful.

01/27/2007, 09:19 AM	#9
RedEyeElf Registered Member Join Date: Dec 2006 Posts: 462	The diffrence really is, the LFS rock is probably cultured, and the Liveaquaria rock is from the ocean Better bio-diversity in the non cultured stuff Fenner talks alot about this in one of his books I have seen lots of diffrent types of cultured rock, pretty sure liveaquaria sells some too Atleast what my friend got from there sure looked like it came from Missouri, then sat in the ocean for acouple months...