Reply to thread

Message

<blockquote data-quote="Acmite" data-source="post: 26832" data-attributes="member: 183">Sapphire and Ruby are both corundum, and according to Moh's hardness scale they have a hardness of 9 (only diamond is harder).&nbsp; Your average pocket knife has a hardness of ~5.5 on this scale.This scale represents the ability of one object to scratch another, so it doesn't take into account how brittle the mineral is or whether or not it can withstand shearing or crushing.Diamonds are used for industrial purposes to cut metal and other substances.&nbsp; These are micro-diamonds and they cut through abrasion.&nbsp; If you had a gem-quality diamond, or any large diamond for that matter, and you dropped it onto cement....let's jut say I would be a little worried.&nbsp; Diamonds are very brittle.&nbsp; In general, the harder the mineral, the more brittle it is.Opal is hydrous silica (kinda like a formless quartz with water in it's structure) and has a hardness of ~6-6.5 (a little less than quartz).&nbsp; You'd be surprised at how resistant opal can be.Since emeralds, rubies, diamonds, etc are fairly hard and brittle to varying degrees (diamond being the most brittle) yet quite hard, I'd probably put them at a hardness of about ~6-7.&nbsp; This places it just below &quot;stone&quot;.&nbsp; Something like quartz I would probably place a little higher, above your avaerage &quot;stone&quot;, maybe ~11-12.I think a quartz statue should definitely have a higher hardness than a generic stone statue.AcmiteGeologist</blockquote>

[QUOTE="Acmite, post: 26832, member: 183"] Sapphire and Ruby are both corundum, and according to Moh's hardness scale they have a hardness of 9 (only diamond is harder). Your average pocket knife has a hardness of ~5.5 on this scale. This scale represents the ability of one object to scratch another, so it doesn't take into account how brittle the mineral is or whether or not it can withstand shearing or crushing. Diamonds are used for industrial purposes to cut metal and other substances. These are micro-diamonds and they cut through abrasion. If you had a gem-quality diamond, or any large diamond for that matter, and you dropped it onto cement....let's jut say I would be a little worried. Diamonds are very brittle. In general, the harder the mineral, the more brittle it is. Opal is hydrous silica (kinda like a formless quartz with water in it's structure) and has a hardness of ~6-6.5 (a little less than quartz). You'd be surprised at how resistant opal can be. Since emeralds, rubies, diamonds, etc are fairly hard and brittle to varying degrees (diamond being the most brittle) yet quite hard, I'd probably put them at a hardness of about ~6-7. This places it just below "stone". Something like quartz I would probably place a little higher, above your avaerage "stone", maybe ~11-12. I think a quartz statue should definitely have a higher hardness than a generic stone statue. Acmite Geologist [/QUOTE]

Verification