You can only get five Радужные куски руды and one Радужная руда per character per week. Resets with the normal weekly reset.
You can only get a certain amount of Радужные куски руды, and the remaining number you can still get for the week can be seen in the profession window when selecting this entry (just called Iridescent Ore) under the section called Appendix I - Boundless Knowledge, it will show as the last line of text on the right. Resets with the normal weekly reset.
All nodes can drop the Радужные куски руды, including elemental nodes, Titan-touched and Infuriated nodes.
Радужная руда is essentially the last Радужные куски руды you can get for the week. So when you get the Радужная руда, that means you will no longer get any Радужные куски руды or Радужная руда on this character for this week.
Primal nodes drop the Заряженный стихиями камень.
Molten nodes drop the Горячий образец руды.
Hardened nodes drop the Неподатливый каменный обломок.
There appears to be no weekly limit on Заряженный стихиями камень, Горячий образец руды or Неподатливый каменный обломок, though they have a significantly smaller drop chance compared to Радужные куски руды and likely do not drop from Titan-Touched, Infuriated, Rich and normal nodes.
Заряженный стихиями камень, Горячий образец руды and Неподатливый каменный обломок all seem to share the same journal entry in the profession window, that being the entry for Заряженный стихиями камень.

Комментарий от Ho1m

and the remaining number you can still get for the week can be seen in the profession window when selecting this entry, it will show as the last line of text on the right

What do you mean? I can't find anything, maybe add a screenshot?

Комментарий от Kaladiel

Hello everyone!
Just like stated by EternalWulf, you can check in your tooltip for Радужные куски руды how many you can still gather per week.
However if you would like to have a look for yourself via scripts here they are, along with the Драконий трактат о горном деле

/script print(C_QuestLog.IsQuestFlaggedCompleted(72160))
/script print(C_QuestLog.IsQuestFlaggedCompleted(72161))
/script print(C_QuestLog.IsQuestFlaggedCompleted(72162))
/script print(C_QuestLog.IsQuestFlaggedCompleted(72163))
/script print(C_QuestLog.IsQuestFlaggedCompleted(72164))

Радужная руда being the last one you can gather for the week.
/script print(C_QuestLog.IsQuestFlaggedCompleted(72165))

Драконий трактат о горном деле
/script print(C_QuestLog.IsQuestFlaggedCompleted(74106))

Комментарий от DocBronner

As of this post I have maxed mining and am still getting the ore fragments. I now have 2 knowledge points that I cannot spend on any specializations.

EDIT UPDATE: You can now trade the extra knowledge for Рвение мастера with Начинающая ремесленница or Начинающая собирательница, who are standing about 20 yards east of the stairs leading up to the crafting orders platform at 37.34, 64.72 in Valdrakken. 10 knowledge for 25 mettle.

Комментарий от Cuffouis

An all-in-one macro to check if the following items have been completed for the week:

Драконий трактат о горном деле x1
Радужные куски руды x5
Радужная руда x1
/run local t={"Crafted",74106,"Blue 1",72160,"Blue 2",72161,"Blue 3",72162,"Blue 4",72163,"Blue 5",72164,"Purple",72165}for i=1,#t-1,2 do print(t,C_QuestLog.IsQuestFlaggedCompleted(t)and "\124cff00ff00Yes" or "\124cffff0000No")end

Items with no weekly limit are the following:

Заряженный стихиями камень
Неподатливый каменный обломок
Горячий образец руды

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Радужные куски руды

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Становится персональным при получении

Использование: Изучить, повышая ваше знание горного дела Драконьих островов на 1.
Требует Горное дело Драконьих островов (25)

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Радужные куски руды

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