Qualifying Child. To be considered a qualifying child, your grandchild must be under the age of 19 on the last day of the tax year, or if he's a full-time student, under the age of 24.No age restrictions apply, however, if your grandchild is permanently and totally disabled.ualifying Child. To be considered a qualifying child, your grandchild must be under the age of 19 on the last day of the tax year, or if he's a full-time student, under the age of 24.
Platinum-iridium alloy. Platinum-iridium alloys are alloys of the platinum group precious metals platinum and iridium. Typical alloy proportions are 90:10 or 70:30 (Pt:Ir). These have the chemical stability of platinum, but increased hardness. The Vickers hardness of pure platinum is 56 HV while platinum with 50% of iridium can reach over 500 HV.
Know the purity content of your platinum ring. As with all precious metals, platinum must be alloyed with other metals in order to achieve the hardness required for jewelry. A ring that is alloyed with 80% Platinum and 20% other metals is worth a lot less than a ring that is 95% pure platinum. 2. Check the hallmark on the inside of the ring. Federal regulations require all platinum bands to bear a stamp or hallmark on the inside of the band.