Original Posted By z4brik►kalau ane kurang sepakat dengan yang agan quote, 999 (99,9%) beda dengan 9995 (99,95%) apalagi dengan yang 9999 (99,99%)

kalau soal titik atau koma atau ditulis dengan persentase itu hanya masalah penulisan, intinya misal 999 atau 99,9 atau 99,90 adalah sama dengan 99,9% yaitu kadar kandungannya sebanyak 99,9% (99,9% mengandung silver)

saat ini yang bisa memurnikan perak sampai 99,99% baru canadian mint. cmiiw

berikut tingkat kemurnian silver

Silver

999.9 (Ultra-fine silver used by Royal Canadian Mint in the Canadian Silver Maple Leaf)
999 (Fine silver used in Good Delivery bullion bars, also known as three nines fine)
980 (common standard used in Mexico ca.1930 - 1945)
958 (equivalent to Britannia silver)
950 (equivalent to French 1st Standard)
925 (equivalent to Sterling silver)
900 (equivalent to Coin silver in the USA, also known as one nine fine)
833 (common standard used in continental silver especially among the Dutch, Swedish, and Germans)
830 (common standard used in older Scandinavian silver)
835 (a standard predominantly used in Germany after 1884)
800 (minimum standard for silver in Germany after 1884; Egyptian silver; Canadian silver circulating coinage)
750 (uncommon silver standard found in older German, Swiss and Austro-Hungarian silver)

bahkan untuk gold ada lagi yang lebih murni dari 99,99% yakni 99,999% yang pernah di produksi perth mint

berikut tingkat kemurnian gold

999.999 (The purest gold ever produced. Refined by the Perth Mint in 1958.)
999.99 (The purest type of gold in the market)
999.9
999 (Fineness equivalent to 24 carat, also known as three nines fine)
995 the minimum allowed in Good Delivery gold bars
990 also known as two nines fine
958.3 (equivalent to 23 carat)
916 (equivalent to 22 carat)
833 (equivalent to 20 carat)
750 (equivalent to 18 carat)
625 (equivalent to 15 carat)
585 (equivalent to 14 carat)
417 (equivalent to 10 carat)
375 (equivalent to 9 carat)
333 (equivalent to 8 carat; minimum standard for gold in Germany after 1884)

sumber : http://en.wikipedia.org/wiki/Millesimal_fineness